JP2018177127A - Longitudinal force controlling apparatus and longitudinal force controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress excess/deficient control.SOLUTION: The longitudinal force controlling apparatus is an apparatus for controlling longitudinal force provided on vehicular wheels. The vehicle travels while the vehicle body is banked under a state where lateral force is provided on the wheels. The apparatus comprises a lateral force obtaining part obtaining lateral force provided on driving wheels, and a controlling part which starts longitudinal force suppression control for suppressing longitudinal force depending on lateral force and change the started longitudinal force suppression control depending on a predetermined traveling mode.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus and method for controlling a longitudinal force acting on a wheel of a vehicle traveling in a banked vehicle with a lateral force acting on the wheel.

  The straddle-type vehicle disclosed in Patent Document 1 includes an ECU that performs traveling control so that the calculated resultant of the longitudinal force and the lateral force does not exceed the range represented by the friction circle.

JP, 2015-085905, A

  In the above-mentioned straddle-type vehicle, since the parameter value used to set the size of the friction circle is uncertain, the control will be overrun.

  An object of the present invention is to provide an apparatus and method capable of suppressing excess and deficiency of control for suppressing longitudinal force.

  A longitudinal force control device according to an aspect of the present invention is a device for controlling longitudinal force acting on a wheel of a vehicle, and the vehicle travels with the vehicle body being banked in a state where lateral force is acting on the wheel Starting the lateral force acquisition control for acquiring the lateral force acting on the wheel, and the longitudinal force suppression control for suppressing the longitudinal force according to the acquired lateral force, and the initiated longitudinal force suppression control And a controller configured to change in accordance with a predetermined traveling state.

  According to the above configuration, since the longitudinal force suppression control for suppressing the longitudinal force is started according to the lateral force, it is possible to prevent the suppression delay of the longitudinal force. By making the suppression tendency different according to the traveling state, it is possible to set the suppression amount according to the traveling state, and even if the parameter for setting the suppression amount deviates from the actual value, excess or deficiency of the suppression amount It can be suppressed.

  When the longitudinal force suppression control is started, the control unit increases the longitudinal force according to the increase of the accelerator opening, and the increase tendency thereof is determined according to the accelerator opening when the longitudinal force suppression control is not performed. It makes it more gentle than the increasing tendency of the non-restraint longitudinal force which is a force, and the control unit prevents the resultant force from exceeding the limit threshold when the traveling condition in which the combined force of the longitudinal force and the lateral force reaches the limit threshold is satisfied. You may control longitudinal force.

  According to the above configuration, even if the parameters are not clear, it is possible to accelerate the start of suppression and to suppress the side slip. It is possible to suppress the sudden occurrence of torque at the time of control return at the beginning of the vehicle's rise.

  The control unit is configured such that the longitudinal force is a non-suppressing longitudinal force which is a longitudinal force determined according to the accelerator opening when the longitudinal force suppression control is not performed until the longitudinal force exceeds a predetermined longitudinal force suppression start threshold. The longitudinal force is controlled, and when the longitudinal force exceeds the longitudinal force suppression start threshold, the longitudinal force suppression control is started to suppress the longitudinal force so that the longitudinal force becomes smaller than the non-suppressive longitudinal force. The control unit controls the longitudinal force such that the resultant does not exceed the limit threshold when the traveling state in which the combined force of the longitudinal force and the lateral force reaches the threshold limit larger than the threshold value for start suppression is satisfied. It is also good.

  According to the configuration, since the suppression control does not start until the start threshold is exceeded, it is possible to prevent the start of the suppression from being undesirably accelerated, and to prevent the feeling from being lowered. It is possible to suppress the sudden occurrence of torque at the time of control return at the beginning of the vehicle's rise.

  The control unit may execute the longitudinal force suppression control according to a suppression tendency configured to be selectable by the driver in advance.

  According to the above configuration, by the driver selecting the suppression tendency, it is possible to execute control in consideration of the driver's request even if the parameter setting is uncertain.

  When the control unit estimates that the vehicle body is in the turning end stage, the control unit may reduce the suppression amount of the longitudinal force compared to before the estimation.

  According to the above configuration, it is possible to easily achieve early acceleration after the end of the turn.

  The control unit may estimate whether or not the vehicle is in the turning end state based on either the driver's operation state or the vehicle's behavior state.

  A slip amount acquisition unit that acquires a slip amount indicating a degree of slip on the road surface with respect to the rotation direction of the wheel, and the control unit when the slip amount exceeds a predetermined slip threshold during execution of the longitudinal force suppression control; The slip suppression control may be executed to increase the amount of suppression of the longitudinal force compared to before that.

  According to the above configuration, since the slip amount based control is avoided, even if the parameter setting is uncertain and the intervention time of the lateral force based control is set a little coarsely, it is easy to prevent the side slip and the excess or deficiency of the longitudinal force suppression control Can be prevented.

  A longitudinal force control device according to another aspect of the present invention is a method of controlling longitudinal force acting on a wheel of a vehicle, wherein the vehicle travels with the vehicle body being banked in a state in which lateral force is acting on the wheel A lateral force acquisition unit that acquires a lateral force acting on the wheel, a control unit that starts longitudinal force suppression control that suppresses longitudinal force according to the acquired lateral force, and a rotation direction of the wheel A slip amount acquisition unit for acquiring a slip amount indicating a degree of slippage to the road surface, and the control unit is configured to be in advance when the slip amount exceeds a predetermined slip threshold during execution of the longitudinal force suppression control; The slip suppression control is executed to increase the amount of suppression of the longitudinal force compared to the above.

  A longitudinal force control method according to an aspect of the present invention is a method of controlling a longitudinal force acting on a wheel of a vehicle, wherein the vehicle travels with the vehicle body being banked in a state where a lateral force is acting on the wheel Starting the step of acquiring the lateral force acting on the wheel, and the longitudinal force suppression control for suppressing the longitudinal force according to the acquired lateral force, and predetermining the initiated longitudinal force suppression control And V. changing according to the state.

  ADVANTAGE OF THE INVENTION According to this invention, the apparatus and method which can suppress the excess and deficiency of control which suppresses longitudinal force can be provided.

FIG. 1 is a perspective view showing a bank state of a motorcycle shown as an example of a vehicle to which a longitudinal force control device according to an embodiment is applied. It is explanatory drawing of a rear wheel friction circle. It is a block diagram showing a wheel slip control device concerning a 1st embodiment. It is a block diagram which shows a limit synthetic force acquisition part and a lateral force estimation part. It is a block diagram showing a control part. It is an explanatory view of a resultant limit value and a longitudinal force limit value. It is a graph which shows an opening degree pattern. It is a flowchart which shows the wheel slip suppression method which concerns on 1st Embodiment. It is a block diagram showing a wheel slip control device concerning a 2nd embodiment. It is explanatory drawing of the 1st and 2nd resultant limit value, and the 1st and 2nd longitudinal force limit value. 5 is a graph showing an opening pattern generated taking into account the first and second longitudinal force limit values. It is a figure which shows the opening degree pattern which concerns on a modification. It is a figure which shows the opening degree pattern which concerns on a modification.

  Hereinafter, embodiments will be described with reference to the drawings. In the following description, the direction is based on the direction seen by the driver. Unless otherwise specified, the term "wheel" refers to an assembly comprising a narrow wheel with hub, rim and spokes, and a tire mounted on the rim and in contact with the road surface. The same applies to subordinate concepts of "wheel", such as "front wheel", "rear wheel", "drive wheel" and "follower wheel".

  The longitudinal force control device 100 (see FIG. 3) according to the present embodiment is a device for controlling the longitudinal force acting on the wheels of the vehicle, thereby preventing or suppressing lateral slip and slip of the wheels against the road surface. . The target vehicle travels by banking the vehicle body in a state where lateral force is applied to the wheels. The motorcycle 1 (see FIG. 1) is a preferred example of such a vehicle. Below, the case where longitudinal force control apparatus 100 controls longitudinal force which acts on a driving wheel especially among wheels is explained.

  As shown in FIG. 1, the motorcycle 1 includes one front wheel 2 and one rear wheel 3. In the present embodiment, the rear wheel 3 is a drive wheel, and the front wheel 2 is a driven wheel. As shown in FIG. 3, the motorcycle 1 is provided with a power source 4 for generating power and a power transmission device 5 for transmitting the power generated by the power source 4 to the drive wheels (rear wheels 3). The wheel (rear wheel 3) is rotationally driven by the power source 4. The power transmission device 5 includes the transmission 6 that increases and decreases the torque according to the transmission gear ratio and outputs it. In the present embodiment, an engine is adopted as the power source 4. As the power source 4, an electric motor may be employed instead of or in addition to the engine.

  As shown in FIG. 1, the motorcycle 1 is provided with a brake device for braking the wheels 2 and 3. The brake device includes a front wheel brake device 7 for braking the front wheel 2 and a rear wheel brake device (drive wheel brake device) 8 for braking the rear wheel 3. The two devices 7, 8 are configured to be operable independently of one another. Both brake devices 7 and 8 are hydraulic, and apply a braking force substantially proportional to the brake hydraulic pressure to the target wheels 2 and 3.

  The motorcycle 1 travels in a straight line with the center line in the vehicle width direction in a front view oriented in the direction perpendicular to the road surface. The motorcycle 1 travels in a bank in which the vehicle body is inclined about the longitudinal axis with respect to the upright state. The “front and rear axis” is a virtual axis and passes through the front wheel contact point and the rear wheel contact point. Hereinafter, the inclination angle around the longitudinal axis of the vehicle body is referred to as “bank angle β”. In the upright state, the bank angle β is zero.

Hereinafter, the force acting on the wheels from the road surface is called "tire force". "Tire force" includes "vertical force" that works vertically upward on the wheel, "longitudinal force" that works in the vertical direction (vehicle length direction) on the wheel, and "lateral force" that works in the lateral direction (vehicle width direction) on the wheel included. Hereinafter, the vertical force acting on the rear wheel 3 (drive wheel) is referred to as “rear wheel vertical force N _r ”, the longitudinal force as “rear wheel longitudinal force F _xr ”, and the same lateral force as “rear wheel lateral force F _yr ” . Also, in order to simplify the explanation, it is assumed that the road surface has no slope and cant. Vertical force is a normal force that acts on the wheel from the road surface as the wheel pushes the road surface downward.

The main factors for generating the rear wheel longitudinal force F _{xr in the} rear wheel 3 are: (1) power generated by the power source 4 and transmitted to the rear wheel 3, (2) rear wheel brake device 8 (see FIG. 1) And the braking force applied to the rear wheel 3 can be mentioned. As shown in FIG. 1, the rear wheel longitudinal force F _xr resulting from the factor (1) is forward (positive value), and propels the vehicle forward. Although detailed illustration is omitted, the rear wheel longitudinal force F _xr resulting from the factor (2) is backward (negative value), and brakes the vehicle moving forward.

The rear wheel lateral force F _yr is generated as a reaction force of centrifugal force mainly based on the traveling speed and the turning radius during turning. In addition, the rear wheel lateral force F _yr is a value related to the time change of the bank angle β (for example, a bank angular velocity β ^· which is a first-order time derivative value of the bank angle β or a second-order time derivative value of the bank angle β A component generated according to a certain bank angular acceleration β ^·· ) is also included. Therefore, the rear wheel lateral force F _yr changes under transitional conditions in which the bank angle β changes (for example, at the beginning or end of turning).

FIG. 2 shows a so-called rear wheel friction circle FCr. “Rear wheel friction circle FCr” is a circle centered on the rear wheel contact point on a horizontal plane perpendicular to the vertical direction and having a radius of magnitude of the maximum frictional force that can occur between the road surface and the rear wheel 3 Say. When the magnitude of the resultant force (sum of vectors) of the rear wheel longitudinal force F _xr and the rear wheel lateral force F _yr becomes larger than the magnitude of the maximum frictional force, the rear wheel 3 slides from the contact point. The origin of the resultant force F _tr is at the center of the rear wheel friction circle FCr (rear wheel contact point). When the end point of the resultant force F _tr is located inside the rear wheel friction circle FCr, the resultant force F _tr applied to the rear wheel 3 from the road surface can be balanced with the frictional force (less than the maximum frictional force). Movement is blocked. When the end point of the resultant force F _tr is located outside the rear wheel friction circle FCr, the resultant force F _tr applied to the rear wheel 3 from the road surface is larger than the maximum frictional force, so the rear wheel 3 slides against the maximum frictional force. Moving. The maximum frictional force is equal to the limit value of the total force (limit total force value) F _tm which prevents the rear wheel 3 from sliding on the road surface. Limit force value F _tm is the coefficient of friction between the road surface and the rear wheel 3 (hereinafter, "road surface friction coefficient") corresponding to the product of the μ and the rear wheel vertical force N _r.

  The longitudinal force control device 100 (see FIG. 3) according to the present embodiment takes into consideration the mechanism of occurrence of the sliding movement of such wheels, and performs the sliding movement of the wheels, at least the sliding movement of the drive wheel (rear wheel 3) Prevent or reduce

  Referring to FIG. 3, the vertical force control device 100 is realized by an on-vehicle controller. Specifically, the controller includes a processor, volatile memory, nonvolatile memory, I / O interface, and the like. The non-volatile memory stores a program related to the procedure of the vertical force suppression method, and the processor executes the program and performs arithmetic processing using the volatile memory. Thus, the vertical force control device 100 is realized.

  The longitudinal force control device 100 is connected to a power adjustment device which is a device for adjusting the power generated by the power source 4. When the power source 4 is an engine, the power adjustment device includes the electronic throttle valve 9, the spark plug 10, and the injector 11. By reducing the opening degree of the electronic throttle valve 9 (hereinafter referred to as “throttle opening degree θ”) and retarding the timing (ignition timing) at which the ignition plug 10 operates, the fuel injection amount from the injector 11 is reduced. The power generated by the power source 4 (engine) can be reduced.

  The longitudinal force control device 100 is connected to a plurality of sensors 12-18 that detect parameter values necessary for performing the longitudinal force control, and the plurality of sensors 12-18 are mounted on the motorcycle 1. The bank angle sensor 12 detects the bank angle β. The vehicle speed sensor 13 detects a vehicle speed V, and the rear wheel speed sensor 14 detects a rear wheel rotational speed Vr. The rear wheel speed sensor 14 may be configured by the same sensor as the vehicle speed sensor 13. The front wheel speed sensor 15 detects a front wheel rotational speed Vf. The gear ratio sensor 16 detects the gear ratio R in the transmission 6 or the gear position of the transmission 6. The engine speed sensor 17 detects an engine speed Ne. The accelerator opening degree sensor 18 detects an accelerator opening degree φ. The accelerator opening degree φ is an operation amount of an accelerator operation member operated by the driver.

  The longitudinal force control device 100 includes a limit resultant force acquisition unit 20, a lateral force estimation unit 30, a control unit 40, an intervention determination unit 60, and a slip degree acquisition unit 61. The intervention determination unit 60 determines success or failure of an intervention condition which is a condition for causing longitudinal force suppression control to suppress longitudinal force. When the intervention condition is satisfied, the control unit 40 “starts” the longitudinal force suppression control that suppresses the longitudinal force according to the lateral force. The intervention condition is, for example, a condition that the bank angle β is a predetermined value or more and the vehicle speed V is a predetermined value or more.

  In this document, "intervention" and "initiation" are terms that represent different concepts. The intervention timing of the vertical force suppression control may coincide with the start timing of the vertical force suppression control or may be earlier than the start timing.

As described later, when the longitudinal force suppression control intervenes, the control unit 40 determines the correspondence (θ _s = f (φ)) between the accelerator opening φ and the command value θ _s of the throttle opening θ. Change the pattern. The opening pattern after change due to control intervention (hereinafter referred to as “suppressed opening pattern”) is the same as the opening pattern before changed (hereinafter referred to as “non-suppressed opening pattern” or “normal opening pattern”). You may overlap. In other words, the command value θ _s determined in accordance with the accelerator opening degree φ in accordance with the restricted opening degree pattern is equal to the command value to be determined in accordance with the accelerator opening degree φ in accordance with the non-suppressed opening degree pattern. A range of the accelerator opening degree φ may exist. Even in the situation where the longitudinal force suppression control intervenes and determines the command value θ _s with reference to the suppression opening pattern, the command value θ _s is the same value as when referring to the non-suppression opening pattern, and the power source 4 It is assumed that vertical force suppression control does not start even though the intervention is performed while the same operation is performed before the intervention. When the command value θ _s determined according to the accelerator opening degree φ with reference to the suppression opening pattern becomes smaller than the command value to be obtained at the time of reference to the non-control opening pattern (thereby, the rear wheel longitudinal force F Longitudinal force suppression control is started when suppression of _xr is achieved. The amount of suppression of the rear wheel longitudinal force F _xr is larger as the command value θ _s at the time of reference to the suppression opening pattern is smaller than the command value to be obtained at the time of reference to the non-control opening pattern.

The limit resultant force acquisition unit 20 is a limit resultant value F that is a limit threshold of the resultant force of the longitudinal force (rear wheel longitudinal force F _xr ) acting on the drive wheel (rear wheel 3) and the lateral force (rear wheel lateral force F _yr ). _{Get tm} . The lateral force estimation unit 30 acquires the lateral force (rear wheel lateral force F _yr ) acting on the drive wheel (rear wheel 3).

Control unit 40 starts longitudinal force suppression control that suppresses longitudinal force in accordance with lateral force. The control unit 40 changes the longitudinal force suppression control according to a predetermined traveling state. The longitudinal force limit value F _xm (see FIGS. 6 and 7) is determined based on the “change longitudinal force suppression control” limit resultant force information and the lateral force information. Then, the vertical force (Kowatateryoku _{F xr)} executes a suppressing vertical force suppression control Tateryoku (Kowatateryoku _{F xr)} so as to be vertical force below the limit value _{F xm.}

Control unit 40, in the vertical force suppression control, sets the opening command value theta _s electronic throttle valve 9, the throttle opening degree to control the electronic throttle valve 9 so that the opening command value theta _s. The throttle opening degree θ and hence the intake amount is suppressed, and the power generated by the power source 4 (engine) is suppressed. Thus, the rear wheel longitudinal force F _xr is suppressed (see the factor (1) described above). At this time, the fuel injection amount may be reduced simultaneously with the reduction of the intake amount for the purpose of maintaining the air-fuel ratio at an appropriate value.

FIG. 4 shows the limit resultant force acquisition unit 20 and the lateral force estimation unit 30. In the present embodiment, the limit force acquisition unit 20 obtains the set value mu _s road friction coefficient, the limit force value F _tm by multiplying the estimated value of the rear wheel vertical force N _r. Therefore, limit resultant force acquisition unit 20 sets vertical force estimation portion 21 for estimating rear wheel vertical force N _r , friction coefficient setting portion 22 for setting a road surface friction coefficient, and resultant force limit value setting portion for obtaining limit resultant value F _tm And 23.

The friction coefficient setting unit 22 prestores a plurality of candidate values μ1, μ2,..., Μn of road surface friction coefficients as an example, and sets these candidate values μ1, μ2,. It is done. The friction coefficient setting unit 22 has a selection unit 22a that selects any one of a plurality of candidate values μ1, μ2,..., Μn. The operating member 19 operated by the driver is mounted on the motorcycle 1, and the driver can select which of the plurality of candidate values μ1, μ2,. The selection unit 22a selects the set value _μs of the road surface friction coefficient according to the input operation result of the driver on the operation member 19.

The vertical force estimation unit 21 and the lateral force estimation unit 30 constitute a tire force estimation unit 50. In other words, the longitudinal force control device 100 includes the tire force estimation unit 50 that estimates the tire force, and the tire force estimation unit 50 includes the vertical force estimation unit 21 that estimates the rear wheel vertical force N _r , and And a lateral force estimation unit 30 for estimating the lateral force F _yr . Hereinafter, the sum of the vertical forces (the front wheel vertical force N _f and the rear wheel vertical force N _{r in} the case of the motorcycle 1) acting on each wheel will be referred to as the “vehicle vertical force N”.

  The vertical force estimation unit 21 obtains the vehicle body vertical force N according to the following equation (1).

N = mg-f _N1 (β ^· , β ^·· ) (= N _f + N _r ) (1)
Here, m is the total mass of the vehicle (the sum of the mass of the vehicle body, the occupant and the load), and g is the gravitational acceleration. mg is the gravity of the vehicle acting at the vehicle center of gravity GC (see FIG. 1). f _N1 (β ^{· · · · ·} ) represents a function having the bank angular velocity β ^{· ·} and the bank angular acceleration β ^{· ·} as variables, and a correction term based on the time change value β ^{· · · · ·} of the bank angle β It is. For example, f _N1 (β ^· , β ^··· ) is an up-down direction that occurs based on the vertical movement of the vehicle gravity center GC due to bank movement (rotational movement around the longitudinal axis) during transitional travel in which the bank angle β changes. The inertial force of

Body vertical force N is the gravity mg, time variation value beta ^· bank angle beta, it is sought by correcting based on beta ^{· ·.} For this reason, the estimation accuracy of the vehicle body vertical force N is improved even during transient traveling (for example, the beginning or the end of turning) in which the bank angle β changes.

Next, the vertical force estimation unit 21 obtains the rear wheel vertical force N _r from the following equation (2).

N _r = N (p−b) / p + f _N2 (β, F _a ) (2)
p is a front-to-rear contact distance between the front wheel contact point and the rear-wheel contact point (hereinafter referred to as “wheel base” for convenience), b is a front-to-back distance from the rear wheel contact point to the vehicle gravity center GC ( See Figure 1). The vehicle body vertical force N is the front wheel vertical force N _f and the rear wheel according to the ratio of the distance (p−b) from the vehicle center of gravity GC to the front wheel contact point and the distance b from the vehicle center of gravity GC to the rear wheel contact point It is distributed to the vertical force N _r .

_Fa is an inertial force in the front-rear direction acting on the vehicle body. f _N2 (β, F _a ) is a function having the bank angle β and inertia force F _a as variables, and represents a function different from the above-described function f _N1 (β ^· , β ^··· ). f _N2 (β, F _a ) is the amount of vertical load transfer to the rear wheel 3 generated based on the inertial force F _a . When the inertial force F _a is backward (mainly in the forward acceleration), a load movement amount to the rear wheel 3 is increased, the rear wheel vertical force N _r increases. The vertical load movement amount is obtained according to the bank angle β (the load movement amount is smaller as the bank angle β is larger). Since the rear wheel vertical force _Nr is determined in consideration of the vertical load distribution amount according to the bank angle β, the estimation accuracy of the tire force in the vehicle traveling with the vehicle banked is improved.

The tire force estimation unit 50 receives the bank angle β detected by the bank angle sensor 12. The tire force estimation unit 50 can calculate the bank angular velocity β ^· and the bank angular acceleration β ^··· by differentiating the input bank angle β. The total vehicle mass m, the wheel base p, and the distance b from the vehicle center of gravity GC to the rear wheel contact point are stored in advance in the tire force estimation unit 50 (handled as a constant). Inertial force F _a can be determined in accordance with the multiplication value of the vehicle total mass m and the longitudinal acceleration a. The tire force estimation unit 50 can obtain the acceleration a by inputting the vehicle speed V detected by the vehicle speed sensor 13 and differentiating the input vehicle speed V. Alternatively, the longitudinal acceleration detected by the longitudinal acceleration sensor may be used.

The resultant force limit value setting unit 23 sets the limit resultant force value based on the rear wheel vertical force N _r estimated by the vertical force estimation unit 21 and the set value μ _s of the road surface friction coefficient set by the friction coefficient setting unit 22. _Find F _tm . For example, the limit resultant value F _tm is the product of the rear wheel vertical force N _r and the set value μ _s .

Hereinafter, the sum of the lateral forces acting on the respective wheels (the front wheel lateral force F _yf and the rear wheel lateral force F _{yr in} the case of the motorcycle 1) is referred to as “vehicle lateral force F _y ”. The lateral force estimating unit 30 obtains the vehicle lateral force Fy from the following equation (3).

F _y = (I _G β ^·· + Ny _G ) / z _G (= F _yf + F _yr ) (3)
Here, I _G is a roll inertia moment of the vehicle body (inertia moment around the longitudinal axis of the vehicle body). y _G is a lateral distance from the wheel contact point to the vehicle gravity center GC, and z _G is a vertical distance from the wheel contact point to the vehicle gravity center GC. Both distances y _G and z _G vary according to the bank angle β.

I _G β ^{· · ·} represents the time change of the angular momentum around the longitudinal axis of the vehicle body in the case of bank movement (when the bank angle β changes). This “time change of angular momentum” is balanced with the sum of the moments given to the vehicle center of gravity around the longitudinal axis. The above equation (3), the time variation I _G beta ^{· ·} angular momentum is given and the moment Ny _G applied to the vehicle center of gravity GC based on the vehicle body vertical force N, the vehicle center of gravity GC based on the vehicle body lateral force F _y moment is a variation of the angular motion equation representing that balance with the sum ^{_{(I G β ·· = -Ny G}} + F y z G) and F _y z _G.

Next, the lateral force estimating unit 30 obtains the rear wheel lateral force F _yr from the following equation (4).

F _yr = F _y (p−b) / p−f _y2 (β, F _a ) (4)
The longitudinal distribution of the vehicle body lateral force F _y is also similar to the longitudinal distribution of the vehicle body vertical force N.

Vehicle body lateral force F _y is the distance from the center of gravity of the vehicle GC until the front wheel contact point (p-b), in accordance with the ratio between the distance b to the rear wheel contact point from the center of gravity of the vehicle GC, and after the front wheel lateral force F _yf It is distributed to the wheel lateral force F _yr .

f _y2 (β, _{F a)} is a function of the variable the bank angle β and the inertia force _{F a,} the above-mentioned function ^{_{f N1 (β ·, β ··}} ) with _{f N2} (β, _{F a)} both Represents a different function. f _y2 (β, F _a ) is a lateral load distribution amount to the front wheel 2 generated based on the inertial force F _a . The lateral load distribution amount is determined according to the bank angle β (the lateral load distribution amount to the front wheel 2 is larger as the bank angle β is larger). Since the rear wheel lateral force F _yr is determined in consideration of the lateral load distribution according to the bank angle β, the estimation accuracy of the tire force in the vehicle traveling with the vehicle banked is improved.

_Fa is an inertial force in the front-rear direction acting on the vehicle body. f _N2 (β, F _a ) is a function having the bank angle β and inertia force F _a as variables, and represents a function different from the above-described function f _N1 (β ^· , β ^··· ). f _N2 (β, F _a ) is the amount of vertical load transfer to the rear wheel 3 generated based on the inertial force F _a . When the inertial force F _a is backward (mainly in the forward acceleration), a load movement amount to the rear wheel 3 is increased, the rear wheel vertical force N _r increases. The vertical load movement amount is obtained according to the bank angle β (the load movement amount is smaller as the bank angle β is larger). Therefore, the estimation accuracy of the tire force in the vehicle traveling with the vehicle body banked is improved.

The roll inertia moment _IG is stored in advance in the tire force estimation unit 50 (handled as a constant). Although the distances y _G and z _G change according to the bank angle β, assuming that the vehicle gravity center GC is a fixed point, the distance from the grounding point to the vehicle gravity center GC can be treated as a constant. The tire force estimation unit 50 can obtain the distances y _G and z _G by multiplying the distance from the contact point to the vehicle gravity center GC by the cosine or sine of the bank angle β.

FIG. 5 shows the control unit 40. FIG. 6 is an explanatory view of the limit resultant force value F _tm and the longitudinal force limit value F _xm . The control unit 40 includes a longitudinal force limit value setting unit 41 that determines a longitudinal force limit value F _mr based on the limit resultant force value F _tm and the rear wheel lateral force F _yr . The longitudinal force limit value F _xm is a value of the rear wheel longitudinal force at which the resultant force of the longitudinal force limit value F _xm and the rear wheel lateral force F _yr currently acting on the rear wheel 3 coincides with the limit resultant force value F _tm is there. The longitudinal force limit value setting unit 41 obtains the longitudinal force limit value F _xm from the following equation (5) according to the _{three-squares} theorem.

F _xm = {F _tm ^2- F _y ² } ^1/2 = {(μN _r ) ^2- F _y ² } ^1/2 (5)
The control unit 40 controls the longitudinal force to be equal to or less than the obtained longitudinal force limit value F _xm . As a result, it is possible to prevent the resultant force of the longitudinal force F _xr acting on the rear wheel 3 and the lateral force F _yr from exceeding the resultant force limit value F _tm .

As an example of the configuration or method for specifically realizing the longitudinal force control, in the present embodiment, the control unit 40 generates a torque generated by the power source 4 (in the present example, the power source 4 is an engine; hereinafter) is, so that less torque limit value tau _m and the corresponding vertical force limit value F _xm, controls the engine torque tau. Then, the throttle opening theta is, so that less opening limit theta _m corresponding to the torque limit value tau _m and thus the vertical force limit value F _xm, controls the throttle opening theta. Therefore, the control unit 40 includes an engine torque limit value setting unit 42, an engine torque conversion coefficient setting unit 43, an opening degree limit value setting unit 44, an engine torque map 45, an opening degree pattern generation unit 46, and an opening degree command value setting unit. It has 47.

Engine torque limit value setting unit 42 determines the engine torque limit value tau _m and the corresponding vertical force limit value F _tm. The engine torque limit value setting unit 42 multiplies the vertical force limit value F _xm set by the vertical force limit value setting unit 41 by the conversion coefficient K _R set by the conversion coefficient setting unit 43 to obtain an engine torque limit. Find the value τ _m . The engine torque τ is increased or decreased according to the speed ratio in the power transmission device 5 and then transmitted to the drive wheels. The conversion factor K _R is set in the light of such background. The conversion factor setting unit 43 determines the speed ratio of the entire power transmission 5 taking into consideration the transmission ratio R in the transmission 6 detected by the transmission ratio sensor 16, and sets the conversion factor K _R based on the speed ratio. Do.

The throttle opening degree θ is a parameter having a large correlation with the engine load, and the engine torque τ is determined based on the engine speed Ne and the engine load (substitutable by the throttle opening degree θ) when the specification of the power source 4 is determined. I can understand. The engine torque map 45 is a correspondence between the engine rotational speed Ne and the engine load, and the engine torque τ, and defines a correspondence (τ = f (Ne, θ)) obtained in advance, which is generally determined. A typical usage is to estimate the engine torque τ from the engine speed Ne and the throttle opening degree θ. On the other hand, the opening limit value setting unit 44 refers to the engine torque map 45, and when the power source 4 is operating at the engine rotational speed Ne detected by the engine rotational speed sensor 17, the engine of the limit value τ _m The throttle opening degree θ necessary to obtain the torque τ is calculated back. Throttle opening determined by the inverse calculation theta is set as the opening degree limit value theta _m.

If it is less than the throttle opening theta is the limit value theta _m, the engine torque tau becomes less than the torque limit value tau _m, Kowatateryoku F _xr becomes vertical force below the limit value F _xm, and after Kowatateryoku F _xr The resultant force F _tr with the wheel lateral force F _yr is less than the limit resultant force value F _tm . In other words, in accordance with the illustration in FIG. 7, the vector representing the resultant force F _tr is contained within the range of a circle in which the limit resultant value F _tm is represented as a circumference. This makes it easy to prevent the drive wheel (rear wheel 3) from slipping on the road surface.

Opening pattern generation unit 46, taking the opening limit theta _m calculated in consideration of the relationship between command values theta _s accelerator opening phi and the throttle opening _{θ (θ s = f (φ} )) Create an opening pattern that defines the

FIG. 7 shows an example of the opening degree pattern. The horizontal axis represents “accelerator opening degree φ” that represents the operation amount in percentage with the maximum operation amount of the accelerator operation member being 100% and the non-operation state being 0%, and the vertical axis represents the fully open position 100 "Throttle opening degree θ" is shown where the opening degree of the electronic throttle valve 9 is expressed as a percentage with the fully closed position being 0%. FIG. 7 also shows, for reference, the normal opening degree pattern P0 in which the longitudinal force is not suppressed (see the two-dot chain line, partially overlapping with other lines). During normal traveling, the accelerator opening φ has a correlation of the opening command value theta _s and approximately linearly. If the accelerator opening degree is 0%, the throttle opening degree is 0%, and if the accelerator opening degree is 100%, the throttle opening degree is 100%.

On the other hand, the opening pattern P1 generated by the opening pattern generation unit 46 of the controller 40, the upper limit of the throttle opening theta is set to the limit value theta _m of less than fully open (100%). Accelerator operation member is in when the unoperated state (when the accelerator opening φ is 0%), the command value theta _s is set to the fully closed (0%).

In opening pattern P1 (see the solid line), as the accelerator opening φ is gradually increased from 0% at the same inclination as the normal opening pattern P0, the command value theta _s is increases linearly. After the command value θ _s thus increased reaches the start threshold θ _ON , it shifts lower than the normal opening pattern P 0. The limit value θ _m is a value larger than the start threshold θ _ON . Hereinafter, for convenience of description, the accelerator opening degree φ _ON corresponding to the start threshold θ _ON according to the normal opening degree pattern P0 is referred to as “start accelerator opening degree”. When the accelerator opening degree φ is in the range from 0% to the start accelerator opening degree φ _ON , the vertical force suppression control does not start even if the intervention is performed. When the accelerator opening φ exceeds the start accelerator opening φ _ON , longitudinal force suppression control is started, and the command value θ _s increases from the start threshold θ _ON with the increase of the accelerator opening φ, but normally It becomes smaller than the command value θ _s determined according to the opening degree pattern P0.

After control initiated, until the throttle opening theta reaches the upper limit theta _m, of which the output increased room is secured (opening pattern P1 corresponding to the increase of the accelerator opening φ which is operated by the driver, Refer to the part moving below the normal opening pattern P0). Thereby, longitudinal force suppression control can be performed according to the driver's acceleration demand. In addition, the output can be increased accelerator opening φ is much, is prevented from exceeding the output corresponding to the limit value theta _m. Therefore, it is possible to suppress the side wheels 3 from slipping according to the principle of the friction circle. Moreover, even if the set value _μs of the road surface friction coefficient and the set value of the weight m deviate from the actual numerical values, the start of longitudinal force suppression control is earlier, so prevention of lateral slip or excessive prevention Side slippage can be easily suppressed. Furthermore, since the output suppression is not performed when the allowance with respect to the friction limit is large until the start of the longitudinal force suppression control, undesired output suppression can be prevented, and a reduction in driving feeling can be prevented.

Figure 7 is a comparative example, to the throttle opening theta reaches the upper limit theta _m does not perform output suppression, and as the throttle opening theta is more than the upper limit theta _m irrespective of the accelerator opening φ , A pattern P ′ in the case of suppressing the output. This pattern P', until the throttle opening theta reaches the upper limit theta _m overlapping with normal running pattern P0. Thereafter, the command value θ _s is leveled off at the limit value θ _m regardless of the increase of the accelerator opening degree φ. In this case, the accelerator opening φ is upon reaching the corresponding opening and the upper limit theta _m during normal reference travel pattern P0, the vertical force suppression control is to start. The start of the longitudinal force suppression control is delayed compared to the opening degree pattern P0.

  In the present embodiment, although the case of curvilinear after the start of the longitudinal force suppression control is illustrated, it may be a linear change (see pattern P22 in FIG. 12). Also, when the accelerator opening reaches 100%, the pattern is set so that the throttle opening θ becomes the upper limit, but the throttle opening becomes the upper limit by the time the accelerator opening reaches 100%. The pattern may be set to (see pattern P21 in FIG. 12).

The command value θ _s is set to the limit value θ _m regardless of the increase of the accelerator opening degree φ. In other words, if the accelerator opening degree φ is less than the opening degree value φ _m associated with the limit value θ _m according to the opening degree pattern P0 during normal traveling, the opening degree setting value θ _m is the same as that during normal traveling obtained in accordance with the accelerator opening phi _m, accelerator opening phi is equal to the opening value phi _m or more, the opening degree setting value theta _s is fixed in the opening limit theta _m.

The opening degree command value setting unit 47 obtains an opening degree command value θ _s with reference to the generated opening degree pattern based on the accelerator opening degree φ detected by the accelerator opening degree sensor 18. Control unit 40, the throttle opening theta controls the electronic throttle valve 9 so that the opening command value theta _s. When the accelerator opening degree φ exceeds the start threshold value φ _ON , longitudinal force suppression control is started, and the opening degree command value θs becomes a smaller value than that at the time of non-suppression.

Returning to FIG. 3, the slip degree acquisition unit 61 acquires slip degree information indicating the degree of slippage of the drive wheel (rear wheel 3) with respect to the road surface. As an example, the slip degree acquiring section 61, a front wheel rotational speed V _f that is detected by the front wheel speed sensor 15, based on the wheel rotation speed V _r after being detected by the rear wheel speed sensor 14, obtains the slip degree. As a specific example, the slip degree wheel rotation speed V after the dividing by the rear wheel rotational speed V _r a speed difference from the rear wheel rotational speed V _r by subtracting the front wheel speed V _f from (1 front wheel rotational speed V _{f It} may be determined by subtracting the speed ratio to _r , and in this case, the larger the value of the degree of slip, the greater the degree of slip. The slip suppression unit 62 executes slip suppression control to reduce the power transmitted from the power source 4 to the drive wheel (rear wheel 3) when the degree of slip exceeds the slip threshold. As a result, the degree of slippage can be reduced to the slip threshold value or less, and the slippage of the drive wheel with respect to the road surface can be reduced within the allowable range.

  FIG. 8 is a flowchart showing a wheel slip suppression method executed by the longitudinal force control device 100. First, slip degree information is acquired, and the slip degree indicated by the slip degree information is compared with the slip threshold (S1). If the degree of slip is less than the slip threshold (that is, if the degree of slip of the drive wheel with respect to the road surface is within the allowable range) (S1: NO), slip suppression control does not intervene. If the slip degree is equal to or more than the slip threshold (that is, if the degree of slip of the drive wheel with respect to the road surface exceeds the allowable range) (S1: YES), slip suppression control intervenes (S2).

  On the other hand, it is determined whether or not the intervention condition of the longitudinal force suppression control is established (S3). If the intervention condition is satisfied (S3: YES), longitudinal force suppression control intervenes (S10). If the intervention condition is not established (S3: NO), the longitudinal force suppression control does not intervene. After the opening setting value of the throttle opening is determined according to the normal opening pattern P0, the electronic throttle valve 9 is controlled (S19).

  The intervention condition is, for example, a condition that the bank angle exceeds a predetermined value (for example, 10 degrees). Longitudinal force suppression control intervenes in a situation where lateral force is produced by the inclination of the vehicle body, and there is a possibility that slippage may occur on the drive wheel due to the lateral force produced on the drive wheel. Conversely, in the upright state, the vertical force suppression control is not intervened (S3: NO), and the power following the accelerator operation is transmitted to the drive wheels. In other words, the throttle opening degree θ is substantially proportional to the accelerator opening degree φ in accordance with the normal opening degree pattern P0 shown for reference in FIG.

  When the longitudinal force suppression control intervenes (S3: YES), road surface information indicating the road surface friction coefficient is acquired (S11), and the vertical force (rear wheel vertical force) acting on the drive wheel is estimated (S12) And limit synthetic force information indicating a limit value of the synthetic force based on the road surface friction coefficient and the estimated value of the rear wheel vertical force (S13). Further, lateral force (rear wheel lateral force) acting on the drive wheel is estimated, and lateral force information is acquired (S14). The longitudinal force limit value is acquired based on the acquired limit synthetic force information and the lateral force information (S15). An engine torque limit value and an opening limit value are obtained based on the longitudinal force limit value (S16), and an opening degree pattern is created based on the opening limit value (S17). The command value of the throttle opening is determined with reference to the opening pattern created based on the accelerator opening (S18), and the throttle valve 9 is controlled so that the throttle opening becomes the command value (S19).

  The power generated by the power source 4 is reduced in both the longitudinal force suppression control and the slip suppression control. When the longitudinal force suppression control and the slip suppression control are both involved, the reduction by the longitudinal force suppression control and the reduction by the slip suppression control may be superimposed. On the other hand, power reduction by longitudinal force suppression control may be stopped, and slip suppression control may be prioritized. In that case, the power of the power source 4 is reduced according to slip suppression control only.

  The longitudinal force control device 100 according to the above configuration includes a limit resultant force acquisition unit 20 for acquiring limit synthetic force information indicating a limit value of resultant force of longitudinal force and lateral force acting on the drive wheel, and lateral force acting on the drive wheel The limit value of the longitudinal force is determined based on the lateral force estimation unit 30 that acquires the lateral force information indicating the and the limit force information and the lateral force information, and the longitudinal force is suppressed so that the longitudinal force becomes less than the limit value. And a control unit that executes force suppression control. First, the limit resultant value is obtained, the rear wheel lateral force currently acting on the drive wheel is estimated, and the relationship between the limit resultant force value and the rear wheel lateral force acting currently (based on the three-square theorem Vertical force limit value. Then, the rear wheel longitudinal force is suppressed so as not to exceed the longitudinal force limit value. Then, it is possible to prevent the combined force of the thus-suppressed rear wheel longitudinal force and the rear wheel lateral force actually acting on the drive wheels from exceeding the limit combined force value. Therefore, it is possible to prevent in advance the undesired drive wheel slippage that occurs when the resultant force exceeds the limit resultant value.

  The slip degree acquisition unit 61 acquires slip degree information indicating the slip degree that is the degree of slippage of the drive wheel with respect to the road surface, and the control unit 40 generates power when the slip degree indicated by the slip degree information exceeds the slip threshold. Slip suppression control to reduce the power transmitted to the drive wheels. Even if an undesired slip occurs in the drive wheel, the slip can be eliminated by the slip suppression control.

  In the present embodiment, the longitudinal force suppression control is changed in accordance with a predetermined traveling state after the suppression control is started. As described above, by starting the suppression before reaching the upper limit value, it is possible to prevent the delay of the longitudinal force suppression control even if the parameter deviates from the actual value. Further, it is possible to suppress the occurrence of excessive suppression with respect to the driver's accelerator request at the start of the longitudinal force suppression control.

Even when the set value μ _s of the road surface friction coefficient, the weight m, and the like are larger than the actual value, the longitudinal force is suppressed by executing the slip suppression control. From this, it is possible to compensate for the side slip suppression control by the slip suppression control, and it is easy to set a large allowable range for the deviation between the parameter and the actual value. For example, since the suppression level can be made different between the slip suppression control and the longitudinal force suppression control, it is possible to divide the situation into different longitudinal forces. By this, it is possible to easily suppress excess or deficiency of slip suppression.

  Further, in this embodiment, the limit total force value and the lateral force are the road surface friction coefficient μ set by the driver, the bank angular velocity, the bank angular acceleration, the front and rear wheel contact point position with respect to the vehicle center of gravity, and the vertical inertia force change. It changes according to the force change and the front / rear distribution ratio of tire force. Thereby, the upper limit value is set accurately. For example, as the vehicle body is returned to the upright state from the maximum bank state, the output suppression amount can be gradually reduced, and a smooth output return feeling according to the return of the bank angle β can be provided.

  Further, by using the intake amount control as longitudinal force suppression, the fuel state is maintained as compared with the ignition thinning and cylinder deactivation control, and it is possible to obtain smooth output suppression in which an impact due to a sharp drop in output is suppressed.

  The limit synthetic force acquisition unit 20 changes the limit synthetic force value according to a selection situation that is different from the lateral force information and the road surface information indicating the slipperiness of the road surface. Depending on the situation, the limit value of the combined force can be changed, and the vertical force limit value determined based on this can also be changed. Therefore, when performing longitudinal force suppression control for suppressing slippage, the degree of the suppression can be changed according to the situation.

  The limit synthetic force acquisition unit 20 selects one of the plurality of synthetic force limit values in accordance with the limit value selection information input by the driver as the selection situation. The degree of suppression of the longitudinal force can be changed according to the driver's request. For example, the driver can set the degree of suppression according to the driving skill. Alternatively, the driver can set the degree of suppression according to the weather. In the present embodiment, it is possible to select from among a plurality of road surface information indicating the road surface friction coefficient, which is one of the parameters necessary for obtaining the resultant limit value, and as a result, one is selected from the plurality of resultant limit values. It will be. It is difficult to estimate the road surface friction coefficient by calculation. Since one of the plurality of friction coefficient candidate values prepared in advance can be selected and the limit total force value can be set stepwise, it becomes easy to realize the suppression control according to the situation.

The limit resultant force acquisition unit 20 may change the resultant limit value in accordance with the behavior of the vehicle body as the selection state. In the present embodiment, wheel vertical force N _r after which one of the parameters required to determine the resultant force limit value, bank angle beta and the associated value beta ^· to the time change, determined based on the beta ^{· ·} The resultant force limit value is changed according to the bank angle β or the like. The degree of suppression of the longitudinal force can be changed according to the behavior of the vehicle body, for example, the bank angle β and its change.

Second Embodiment
The second embodiment will be described below. The present embodiment differs from the first embodiment in that two limit resultant values are set, and the second embodiment will be described focusing on this difference.

As shown in FIG. 9, in the wheel slip suppression apparatus 200 according to the present embodiment, the resultant force limit value setting unit 223 of the limit resultant force acquisition unit 220 is the set value μ _{s of the} road surface friction coefficient in the same manner as the first embodiment. A first resultant force limit value F _tm1 is determined based on the rear wheel vertical force N _r and the rear wheel vertical force N _r . Further, the resultant force limit value setting unit 223 obtains a second resultant force limit value _Ftm2 based on the set value _μs of the road surface friction coefficient and the vehicle vertical force N. Also first force limit value _{F tm1} The second force limit value _{F tm2,} a force N, the product of the _{N r} and the corresponding set value mu _s road friction coefficient. The longitudinal force limit value setting unit 241 obtains the first and second resultant force limit values F _tm1 and F _tm2 from the limit resultant force acquisition unit 220, and obtains an estimated value of the rear wheel lateral force F _yr from the lateral force estimation unit 30. . As in the first embodiment, the longitudinal force limit value setting unit 241 _obtains a first longitudinal force suppression value F _xm1 corresponding to the first limit resultant force value F _tm1 according to the _{three-squares} theorem. Further, a second longitudinal force suppression value F _xm2 corresponding to the second limit resultant force value F _tm2 is determined.

In FIG. 10, two resultant force limit values F _tm1 and F _tm2 are illustrated. As shown in FIG. 11, the vehicle body vertical force N is, since the power of prior to dispensing the vertical force to the rear wheel 3 and the front wheel 2, than the rear wheel vertical force N _r takes a large value. In other words, the vehicle body vertical force N corresponds to the vertical force that should be acting on the rear wheel 3 when assuming that the vertical force distributed to the front wheels 2 is zero, and the vehicle body vertical force N has a certain value Corresponds to the maximum vertical force that can act on the rear wheel 3. Therefore, the second resultant force limit value F _tm2, even set value mu _s road friction coefficient used for the calculation are the same, takes a value greater than the first force limit value F _tm1. Further, the second longitudinal force suppression value F _xm2 takes a value larger than the first longitudinal force suppression value F _xm1 even if the estimated value of the rear wheel lateral force F _yr used in the calculation is the same.

Returning to FIG. 9, the engine torque limit value setting unit 242 sets a first engine torque limit value τ _m1 corresponding to the first longitudinal force suppression value F _xm1 by the same calculation method as in the first embodiment. Further, the first opening limit value θ _m1 is set in the opening limit value setting unit 244. Further, the second engine torque limit value τ _m2 corresponding to the second longitudinal force suppression value F _xm2 is set in the engine torque limit value setting unit 242, and the second opening limit value θ _m2 is the opening limit value setting unit. It is set at 244. The opening degree pattern generation unit 246 generates an opening degree pattern P10 different from that during normal traveling, taking into consideration the first opening degree limit value and the second opening degree limit value.

As an example is shown in FIG. 11, the opening degree pattern P10 has a first opening degree pattern P10a for setting the opening degree command value θ _s from 0% to the first opening degree limit value, and the opening degree command value θ The second opening degree pattern P10 b is configured to set _s between the first opening degree limit value and the second opening degree limit value. In the present embodiment, the first opening pattern P10a is the same as the opening pattern P0 of normal running, the opening command value theta _s substantially proportional to the accelerator opening phi. The opening degree command value θ _s is an opening degree value (hereinafter referred to as “switching opening degree φ _m1 ”) in which the accelerator opening degree φ is associated with the first opening degree limit value according to the opening degree pattern P0 during normal travel. Sometimes, the first opening limit value θ _m1 is set. In the first embodiment, the opening command value θ _s is set so as not to exceed the first opening limit value θ _m1 based on the rear wheel vertical force N _r during the longitudinal force suppression control, but the present embodiment Then, when the accelerator opening degree φ exceeds the switching opening degree φ _m1 , the opening degree command value θ _s is within the range of less than the second opening degree limit value θ _m2 according to the second opening degree pattern P10 b. It is set to a value larger than the value θ _m1 . In the second opening pattern P10b, as an example, as the accelerator opening φ increases from the switching opening φ _m1 to 100%, the opening setting value θ _s is changed from the first opening limit value θ _m1 to the second opening limit It is a pattern that linearly increases to the value θ _m2 .

  The limit resultant force acquisition unit 220 selects one of the plurality of resultant force limit values according to the driving operation related to the fluctuation of the torque transmitted to the drive wheel as the selection situation. In the present embodiment, the combined force limit value is substantially selected from the first resultant limit value and the second combined limit value depending on whether the accelerator opening degree φ exceeds the switching opening degree φm1. There is. Thus, the degree of suppression of the longitudinal force can be changed according to the torque transmitted to the drive wheel.

  The control unit 240 determines the first longitudinal force limit value as the longitudinal force limit value if the corner escape condition that the vehicle turning is leaving the corner is not satisfied, and if the corner escape condition is satisfied, As a longitudinal force limit value, a second longitudinal force limit value larger than the first longitudinal force limit value is determined. The corner exit condition is set based on the acceleration request from the driver. In the present embodiment, the corner escape condition is a condition that the accelerator opening degree φ exceeds the switching opening degree φm1. After leaving the corner, the degree of suppression of the longitudinal force decreases, and a large torque can be applied to the drive wheel. Therefore, in the transition from turning to straight running, the suppression of the longitudinal force does not become excessive, and the acceleration is improved.

  In the present embodiment, when the first limit circle is reached and the accelerator is further opened, it is set to allow the torque to be output to the second limit circle. Thus, the driver's intention can be prioritized up to the first limit circle. Further, after the first limit circle is exceeded, the amount of suppression gradually intensifies in accordance with the accelerator opening degree φ. This leaves room for the increase in output even after exceeding the first limit circle, thereby preventing a decrease in responsiveness to a request for increase in output at the beginning of the return from the bank state to the upright state, for example, at the corner escape. In addition, it is possible to obtain smooth acceleration by suppressing the torque change shock due to the cancellation of the output suppression.

  The second limit value may be set to a value larger than the first limit value, and may be a value different from μN. Conversely, the first limit value may be set to a value smaller than the second limit value, and may be set to a value different from μNr. In this manner, the lateral slip suppression effect can be obtained and excessive suppression can be prevented by changing the suppression amount in stages even when the road surface friction coefficient μ and the weight m are uncertain. For example, in the embodiment, the second limit value is set by estimating the vehicle body vertical force, but the resultant force that actually causes a side slip by the measured value may be stored in advance.

  From the first limit value to the second limit value, the output is suppressed while permitting the output increase. Further, the throttle opening is set to the second limit value or less regardless of the accelerator opening φ. Thus, by setting two limit values, a plurality of sideslip suppression levels are prepared. Thereby, even if the road surface friction coefficient μ is uncertain, it is easy to realize control according to the situation. The rider's intention or the vehicle behavior may be used as a condition for the gradual suppression of sideslip. The rider's intention includes the preset operation and the operation during traveling, and the operation during traveling includes the throttle opening degree, the change rate of the throttle opening degree, the gear change operation and the like. The behavior of the vehicle includes a skid state, a turning state, a steering state, a corner exit and the like.

  In the above embodiment, as control using double friction circles, the value of vertical force (rear wheel vertical force) between the inner friction circle (first limit value) and the outer friction circle (second limit value) However, double friction circles (first limit value and second limit value) may be set by changing the value of the road surface friction coefficient. In this case, when the road surface friction coefficient for setting the first limit value is the first road surface friction coefficient, and the road surface friction coefficient for setting the second limit value is the second road surface friction coefficient, the first road surface friction is The factor and / or the second road surface friction factor may be set by the driver. When the driver is set, as described in the first embodiment, the control unit stores the set values of the plurality of road surface friction coefficients as candidates so that the driver can select from among a plurality of candidate values. May be When the driver is allowed to select one of the first road surface friction coefficient and the second road surface friction coefficient, the road surface friction coefficient on the side which is not selected can not be selected by multiplying the selected value by a predetermined coefficient. It may be set automatically by the control unit.

(Modification)
Although the embodiments have been described above, the above configurations and methods can be modified, added or deleted within the scope of the present invention.

In the above embodiment, the limit total force value is changed according to the limit value selection information input by the driver at the operation member 19. Alternatively, it is changed (based on whether the accelerator opening degree φ exceeds the switching opening degree φm1) according to the accelerator opening degree φ as an example of the driving operation related to the fluctuation of the torque transmitted to the drive wheel. Alternatively, the vehicle body bank angle beta and its time variation beta ^· as an example of a behavior is changed in accordance with the beta ^{· ·.} As another example of the driving operation related to the torque fluctuation, the limit total force value may be changed according to the change amount of the throttle opening degree, the change amount of the accelerator opening degree, and the shift operation. As another example of the vehicle behavior, the limit total force value may be changed according to the skid state, the turning state, and the steering state.

In the above embodiment, the corner exit condition is the condition that the accelerator opening degree φ is equal to or greater than the switching opening degree φ _m1 . Besides this, the condition may be that the bank angle β becomes less than the second predetermined value after exceeding the first predetermined value, and the second predetermined value becomes a value smaller than the first predetermined value. It is preferable that hysteresis be present at two predetermined values.

  Tailing control may be performed to gradually restore the power generated by the power source 4 at the end of the longitudinal force suppression control.

  In acceleration of the vehicle, the electronic throttle valve, spark plug and injector operate to increase the power, and in response, the torque generated by the power source 4 is increased, and the increased torque is transmitted through the power transmission 5 It is realized through the process that the rotational acceleration of the drive wheel is increased. For this reason, there is a time lag between the time when the vehicle is actually accelerated after the operation command is given to the electronic throttle valve, the spark plug and the injector.

Here, according to the arithmetic expression (2), a rear wheel vertical force Nr is sought taking into account the inertial force Fa in the longitudinal direction, the inertial force F _a is determined in accordance with the longitudinal acceleration of the vehicle body. The presence of the time lag, the rear wheel vertical force N _r estimated by vertical force estimating section 21, the current state of the electronic throttle valve, there is a possibility that the response delay occurs with respect to the operating state of the spark plug and the injector. Therefore, the arithmetic expression (2) may be changed to the following expression (2) ′.

N _r = N (p−b) / p + f _N2 (β, θ, Ne) (2) ′
As described above, the throttle opening has a strong correlation with the engine load, and if the engine load and the engine speed are determined, the torque currently generated by the power source 4 (engine) can be estimated with reference to the engine torque map. . In the aforementioned acceleration process, it is possible to estimate the rear wheel vertical force N _r using parameters on the more upstream side, and it is possible to obtain an estimation result in which the delay with respect to the operating state of the power source 4 is suppressed. This makes it easier to prevent slippage of the drive wheels on the road surface.

  It may be a vehicle that turns in a bank, and may be, for example, a tricycle other than a motorcycle. In the present embodiment, although the longitudinal force control device is realized by the engine control device, it may be realized by a control device different from the engine control device. In addition, a program for preventing skidding may be newly stored in the existing engine control device to function as a skidding suppression device. Further, it may be realized by one control device, or may be divided into a plurality of control device units for each of one or a plurality of operation units.

  In this embodiment, by controlling the intake amount, the driving force, and hence the longitudinal force corresponding to the reaction force of the driving force is suppressed, but the known control object contributing to the controllable output suppression other than the intake amount To control the longitudinal force. For example, the ignition timing may be retarded, or ignition thinning, misfire processing, or fuel injection stop processing may be performed. Thus, the present invention can be applied to a model in which the intake amount is not electronically controlled by suppressing the longitudinal force by performing the ignition control or the fuel injection amount control. For example, the longitudinal force may be suppressed by controlling the rear wheel braking device and the clutch device, and the transmission may control the transmission ratio of the continuously variable transmission. Further, in addition to the side slip suppression control, when the suspension can be electronically controlled, the load on the rear wheel may be increased by controlling the pitching posture at the time of turning, in which case the command value to the suspension Correspondingly, the estimated value of the vertical force and thus the resultant limit value may be controlled to be large.

  In the present embodiment, the driver can set the road surface friction coefficient, but instead of enabling the setting value of the road surface friction coefficient to be selectable, the driver is a correction coefficient as a slip suppression support amount, and the road surface The longitudinal force control device may be configured to be able to set a correction coefficient to be multiplied by the friction coefficient. In this case, the amount of suppression of the longitudinal force increases as the correction coefficient decreases. For example, when the driver sets the correction coefficient, the output at the time of turning is suppressed by giving the driver a sense of power of the small displacement engine and the response. By appropriately selecting and setting the correction coefficient, it is possible to select the slip suppression support amount at the time of turning.

In the present embodiment, although the accelerator opening degree φ and the throttle opening degree θ are in direct proportion during non-suppression control in order to facilitate understanding, the present invention is not limited to this. For example, depending on the driving feeling of the driver, the output characteristics of the engine, the fuel efficiency, the exhaust gas regulation, etc., it may be different from the direct proportion. For example, it may be set in accordance with a reference correlation rule indicating the relationship between the accelerator opening degree φ and the throttle opening degree θ. In such a case, when this control is executed, it operates in accordance with the reference correlation rule until suppression is started. When the suppression is started, the throttle opening degree by the suppression control may be a value obtained by multiplying the throttle opening degree θ obtained by the reference correlation rule by the correction value. The throttle opening theta by suppression control, after setting the upper limit value theta _m, to reach the upper limit value is set from the start suppressed to increase with an increase in accelerator opening phi. The correction value may be set to a value of 1 or less, and may be set to decrease as the accelerator opening degree φ increases after the control starts. As a result, as the accelerator opening degree φ increases, the suppression amount of the throttle opening change with respect to the driver's accelerator opening request becomes larger.

The opening pattern is not limited to the one described above or as shown in FIGS. As shown in FIG. 13, regardless of the accelerator opening degree φ, the opening setting value set at the time of execution of longitudinal force suppression control is smaller than the opening degree setting value to be determined at the time of non-execution of longitudinal force suppression control It may be a value. In that case, the throttle opening 0% (full closing) is the start threshold, and the accelerator opening 0% is the start accelerator opening φ _ON. Therefore, the intervention timing of the longitudinal force suppression control matches the start timing of the longitudinal force suppression control Do. In that case, the increasing tendency of the longitudinal force (opening degree setting value) according to the increase of the accelerator opening degree φ may be gentler than the increasing tendency of the normal opening degree pattern. As an example, next to the throttle opening theta 0% when the accelerator opening φ is 0% accelerator opening φ may become the throttle opening theta is the limit value theta _m at 100%. The increasing tendency may be non-linear (see opening pattern P23) or linear (see opening pattern P24).

100 Wheel slip suppression device 3 Drive wheel 20 Limit resultant force acquisition unit 30 Lateral force estimation unit 40 Longitudinal force estimation unit 61 Slip degree acquisition unit 62 Slip suppression unit N Body vertical force F _y Body lateral force N _r Rear wheel vertical force F _{yr Back} Wayokoryoku _{F xr} Kowatateryoku _{F tr} resultant force _{F tm} limit force value _{F tm1} first limit force value _{F tm2} second limit force value _{F xm} vertical force suppression value _{F xm1} first vertical force suppression value _{F xm2} second vertical Force suppression value μ Road friction coefficient

Claims (9)

A device for controlling a longitudinal force acting on a wheel of a vehicle, wherein the vehicle travels with the vehicle body being banked in a state where a lateral force is acting on the wheel,
A lateral force acquisition unit for acquiring lateral force acting on the wheel;
A longitudinal force control device comprising: a control unit that starts longitudinal force suppression control that suppresses longitudinal force according to the acquired lateral force, and changes the started longitudinal force suppression control according to a predetermined traveling state. When the longitudinal force suppression control is started, the control unit increases the longitudinal force according to the increase of the accelerator opening, and the increase tendency thereof is determined according to the accelerator opening when the longitudinal force suppression control is not performed. Make it gentler than the increasing trend of non-restraint longitudinal force
The longitudinal force control according to claim 1, wherein the control unit controls longitudinal force such that the resultant force does not exceed the limit threshold when satisfying a traveling state in which the combined force of the longitudinal force and the lateral force reaches a limit threshold. apparatus. The control unit
Until the longitudinal force exceeds a predetermined longitudinal force suppression start threshold, the longitudinal force is controlled so as to become the non-suppressive longitudinal force which is the longitudinal force determined according to the accelerator opening when the longitudinal force suppression control is not performed. ,
When the longitudinal force exceeds the longitudinal force suppression start threshold, the longitudinal force suppression control is started to suppress the longitudinal force so that the longitudinal force becomes smaller than the non-suppressing longitudinal force.
The control unit controls the longitudinal force such that the resultant does not exceed the limit threshold when the traveling state in which the combined force of the longitudinal force and the lateral force reaches a limit threshold larger than the longitudinal force suppression start threshold is satisfied. The longitudinal force control device according to claim 1.   The longitudinal force control device according to any one of claims 1 to 3, wherein the control unit executes the longitudinal force suppression control according to a suppression tendency configured to be selectable in advance by a driver.   The longitudinal force control device according to any one of claims 1 to 4, wherein when the control unit estimates that the vehicle body is in the turning end stage, the amount of suppression of the longitudinal force is reduced compared to before the estimation.   The longitudinal force control device according to claim 5, wherein the control unit estimates whether or not the vehicle is in the direction change end state based on either the driver's operation state or the vehicle's behavior state. A slip amount acquisition unit that acquires a slip amount indicating a degree of slippage relative to the road surface with respect to the rotation direction of the wheel;
The control unit executes slip suppression control to increase the suppression amount of the longitudinal force when the slip amount exceeds a predetermined slip threshold while the longitudinal force suppression control is being performed. The longitudinal force control device according to any one of 6. A device for controlling a longitudinal force acting on a wheel of a vehicle, wherein the vehicle travels with the vehicle body being banked in a state where a lateral force is acting on the wheel,
A lateral force acquisition unit for acquiring lateral force acting on the wheel;
A control unit that starts longitudinal force suppression control that suppresses longitudinal force according to the acquired lateral force;
A slip amount acquisition unit that acquires a slip amount indicating a degree of slippage relative to the road surface with respect to the rotation direction of the wheel;
When the slip amount exceeds a predetermined slip threshold during execution of the longitudinal force suppression control, the control unit executes the slip suppression control to increase the suppression amount of the longitudinal force compared to that before the longitudinal force control device. . A method of controlling longitudinal force acting on a wheel of a vehicle, wherein the vehicle travels with the vehicle body being banked in a state where lateral force is acting on the wheel,
Acquiring a lateral force acting on the wheel;
A longitudinal force control method comprising the steps of: starting longitudinal force suppression control for suppressing longitudinal force according to the acquired lateral force; and changing the started longitudinal force suppression control according to a predetermined traveling state.

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