Control device for vehicle

Abstract

To estimate a vertical load on at least one of front and rear wheels by a simple method using general-purpose detection means.SOLUTION: A control device 10 for a vehicle 1 which includes yaw rate detection means 21 and lateral acceleration detection means 22, comprises: a roll angle acquisition unit 11 that acquires a roll angle θ of the vehicle 1; a load movement amount estimation unit 12; and a vertical load estimation unit 13. The load movement amount estimation unit 12 estimates at least one of a load movement amount Δwy_f between left and right wheels of front wheels 2F on the basis of the roll angle θ, lateral force Yf of the front wheels 2F, front wheel roll attenuation coefficient cf, and front wheel roll stiffness kf and a load movement amount Δwy_r between the left and right wheels of rear wheels 2R on the basis of the roll angle θ, lateral force Yr of the rear wheels 2R, rear wheel roll attenuation coefficient cr, and rear wheel roll stiffness kr. The vertical load estimation unit 13 estimates the vertical loads Z1 to Z4 of at least one wheel 2 of the front and rear wheels 2F, 2R for which the load movement amounts Δwy_f, Δwy_r are estimated on the basis of the estimated load movement amounts Δwy_f, ΔWy_r.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device for estimating the vertical load of at least one of the front and rear wheels of a vehicle.

Background Art

[0002] A plurality of detection means (for example, sensors) for detecting the running state, the state of in-vehicle devices, etc. are provided in a vehicle, and various vehicle motion controls are carried out based on the detection values. For example, Patent Document 1 discloses various devices that calculate and output state quantities related to the vehicle state from the detection results of various sensors. In this device, the ground load variation, which is the variation in the ground load (vertical load) of the wheels, is calculated, and by using this ground load variation as an input value for feedback control, it is possible to make an estimation considering the load variation caused by road surface displacement (disturbance). Note that Patent Document 1 discloses a technique for controlling the damping force of the suspension and the torque of the steering using this estimation result.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique of Patent Document 1 described above, the ground load variation is calculated with reference to the wheel angular velocity, the estimated values of the front and rear speeds before the spring, the estimated value of the pitch rate, and the estimated value of the yaw rate. Thus, in the technique of Patent Document 1, an attempt is made to realize advanced vehicle body attitude control including roll, pitch, and bounce. As a result, the number of state quantities to be estimated is large and the calculation is complicated. Therefore, in vehicles where advanced vehicle body attitude control is not required up to this point, if the ground load can be estimated by a simpler method and using general-purpose detection means that are standard equipment for vehicles, it can be utilized for various vehicle motion controls.

[0005] This invention was devised in view of such problems, and one of its objectives is to provide a vehicle control device that estimates the vertical load on at least one of the front and rear wheels by a simple method using general-purpose detection means. Note that, not limited to this objective, another objective of this invention is to achieve operational effects that are not obtainable by conventional techniques and that are derived from each configuration shown in the embodiments for carrying out the invention described below.

Means for Solving the Problems

[0006] The disclosed vehicle control device can be realized as the following disclosed aspects or application examples, and solves at least some of the above problems. The disclosed vehicle control device is applied to a vehicle provided with yaw rate detection means for detecting the yaw rate of the vehicle and lateral acceleration detection means for detecting the lateral acceleration of the vehicle. The control device includes a roll angle acquisition unit that acquires the roll angle of the vehicle, and a load movement amount estimation unit that estimates at least one of the load movement amounts between the left and right wheels of the front wheels based on the acquired roll angle, the lateral force of the front wheels, the front wheel roll damping coefficient related to the front wheels, and the front wheel roll stiffness related to the front wheels, and the load movement amount between the left and right wheels of the rear wheels based on the acquired roll angle, the lateral force of the rear wheels, the rear wheel roll damping coefficient related to the rear wheels, and the rear wheel roll stiffness related to the rear wheels. The control device further includes a vertical load estimation unit that estimates the vertical load of each of at least one of the front wheels and the rear wheels for which the load movement amount has been estimated, based on the estimated load movement amount.

Effects of the Invention

[0007] According to the disclosed vehicle control device, the vertical load (ground load) of each of at least one of the front and rear wheels can be estimated by a simple method using general-purpose detection means.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0009] With reference to the drawings, a control device for a vehicle as an embodiment will be described. The embodiments shown below are merely examples, and there is no intention to exclude various modifications and applications of technologies not explicitly shown in the following embodiments. The configurations of each embodiment can be variously modified and implemented without departing from their gist. Also, they can be selected as needed or combined as appropriate. In the following description, the forward direction of the vehicle is taken as the front (front of the vehicle), and the left and right are defined based on the front.

[0010] [1. Device Configuration] The control device 10 of the present embodiment is applied to the vehicle 1 illustrated in FIG. 1 and has a function of estimating at least the vertical load (also called the ground load or wheel load) of one of the front wheels 2F and the rear wheels 2R of the vehicle 1. The control device 10 is a device realized by one of the electronic control units (ECUs, Electronic Control Units) mounted on the vehicle 1. The control device 10 is equipped with a processor (microprocessor) such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and a ROM (Read Only Memory), a RAM (Random Access Memory), a non-volatile memory, etc.

[0011] The processor is an arithmetic processing unit that incorporates a control unit (control circuit), an arithmetic unit (arithmetic circuit), a cache memory (register group), etc. Also, ROM, RAM, and non-volatile memory are memory devices in which programs and working data are stored. The estimation content implemented by the control device 10 is recorded and stored in the memory as firmware or an application program. When the program is executed, the content of the program is expanded within the memory space and executed by the processor.

[0012] The type of the vehicle 1 is not particularly limited, and it is applicable to engine vehicles, electric vehicles (EV; Electric Vehicle, HEV; Hybrid Electric Vehicle, PHEV; Plug-in Hybrid Electric Vehicle), and fuel cell vehicles (FCV; Fuel Cell Vehicle). The vehicle 1 is equipped with an actuator related to the operation of the vehicle 1 and a notification device that announces to the driver by voice or display. Examples of the actuator include a drive source such as an engine or an electric motor, a brake device that independently brakes each wheel 2, a power steering device, AFS (Active Front Steering) and ARS (Active Rear Steering) that can actively control the steering amounts (front wheel steering angle, rear wheel steering angle) of the front wheels 2F and the rear wheels 2R, and an active suspension.

[0013] The actuator is a device that plays a role in converting energy into mechanical displacement or stress, and is individually controlled by an in-vehicle control device (not shown). An individual in-vehicle control device may be provided for each actuator, or a common in-vehicle control device may control different actuators. Also, the in-vehicle control device that controls the notification device may be provided separately from the in-vehicle control device that controls the actuator. In the present embodiment, the estimation result estimated by the control device 10 is sent to each in-vehicle control device and used for controlling the actuator and the notification device. Note that the control device 10 may also have a function of controlling the actuator and the notification device. That is, the control device 10 may be configured to have both an estimation function and a control function.

[0014] The vehicle 1 is provided with sensors for acquiring various information of the vehicle 1. In the example shown in FIG. 1, a yaw rate sensor 21, a lateral acceleration sensor 22, and a longitudinal acceleration sensor 23 are provided, and each of the sensors 21 to 23 is connected to the control device 10. The yaw rate sensor 21 (yaw rate detection means) is a sensor that detects the rotational angular velocity around the vertical axis passing through the center of gravity G of the vehicle 1 as the yaw rate r. In the present embodiment, as shown by the thick arrow in FIG. 1, the yaw rate r is defined such that the counterclockwise direction of the center of gravity G is the positive direction when the vehicle 1 is viewed from above.

[0015] The lateral acceleration sensor 22 (lateral acceleration detection means) and the longitudinal acceleration sensor 23 (longitudinal acceleration detection means) are sensors that respectively detect the lateral acceleration A y and the longitudinal acceleration A x at the center of gravity G of the vehicle 1. In the present embodiment, as shown by the thick arrow in FIG. 1, the lateral acceleration A y is defined such that the leftward direction from the center of gravity G is the positive direction, and the longitudinal acceleration A x is defined such that the direction forward from the center of gravity G is the positive direction. The information detected by each of the sensors 21 to 23 is sent to the control device 10. In addition to these sensors 21 to 23, the vehicle 1 may be provided with general-purpose sensors such as a vehicle speed sensor for detecting the vehicle body speed, a wheel speed sensor for detecting the wheel speed, and a steering angle sensor for detecting the steering angle.

[0016] The means for detecting the yaw rate r, the means for detecting the lateral acceleration A y and the means for detecting the longitudinal acceleration A x are not limited to the yaw rate sensor 21, the lateral acceleration sensor 22, and the longitudinal acceleration sensor 23. For example, the lateral acceleration A y may be estimated based on the steering angle and the vehicle body speed, or the estimated value and the value detected by the lateral acceleration sensor 22 may be corrected based on another sensor value to detect (acquire) the lateral acceleration A y . Similarly, the value detected by the yaw rate sensor 21 and the value detected by the longitudinal acceleration sensor 23 may be corrected based on another sensor value to correct the yaw rate r and the longitudinal acceleration A xIt may be detected (acquired). In such a case, the estimation unit or the correction unit (functional elements of the control device) can serve as each detection means.

[0017] [2. Control Configuration] The control device 10 of the present embodiment uses the information detected by various sensors 21 to 23 to estimate at least one of the vertical loads Z 1 , Z 2 of the front wheels 2F of the vehicle 1 and the vertical loads Z 3 , Z 4 of the rear wheels 2R. Further, the control device 10 also has a function of estimating the lateral forces Y 1 ~Y 4 of the wheels 2 corresponding to the estimated vertical loads.

[0018] For example, when the control device 10 has a function of estimating only the vertical load Z 3 , Z 4 of the rear wheels 2R, it can also have a function of estimating the lateral force Y 3 , Y 4 of the rear wheels 2R. In the present embodiment, the case of estimating the vertical loads Z 1 ~Z 4 of all four wheels is exemplified, and the lateral forces Y 1 ~Y 4 of all four wheels are also estimated. Here, in the symbols indicating the vertical loads Z 1 ~Z 4 and the lateral forces Y 1 ~Y 4 the subscript numbers 1 to 4 are attached in the order of the left front wheel 2FL, right front wheel 2FR, left rear wheel 2RL, and right rear wheel 2RR.

[0019] The control device 10 includes a roll angle acquisition unit 11, a load movement amount estimation unit 12, and a vertical load estimation unit 13 as functional elements for estimating the vertical loads Z 1 ~Z 4 . Further, the control device 10 of the present embodiment uses the estimated vertical loads Z 1 ~Z 4 to estimate the lateral forces Y 1 ~Y 4As a functional element for estimating, it further includes a lateral force estimation unit 14. These elements are for the convenience of classifying and showing the functions of the control device 10. These elements can be each described as an independent program, and can also be described as a composite program combining a plurality of elements. The programs corresponding to each element are stored in the memory or storage device of the control device 10 and executed by the processor.

[0020] The roll angle acquisition unit 11 acquires the roll angle θ of the vehicle 1. The method for acquiring the roll angle θ is not particularly limited. Similar to the above sensors 21 to 23, a sensor capable of detecting the roll angle θ may be provided, and the sensor value or the corrected value of the sensor value may be acquired as the roll angle θ. Alternatively, the value (roll angle θ) may be acquired by estimating the roll angle θ based on the sensor value and vehicle specifications. Here, an example of the latter method, that is, the method of estimating and acquiring the roll angle θ, will be described.

[0021] The roll angle acquisition unit 11 is the lateral acceleration A detected by the lateral acceleration sensor 22 y and the front-wheel roll damping coefficient c for the front wheels 2F f and the rear-wheel roll damping coefficient c for the rear wheels 2R r Based on the sum of the vehicle roll damping coefficient c (= c f + c r ), the roll angle θ of the vehicle 1 is estimated. As shown in FIG. 2, the vehicle roll damping coefficient c is the proportionality constant (roll-direction damping coefficient) of the component proportional to the roll angular velocity among the moments that resist roll motion. The front-wheel roll damping coefficient c f is, as shown in FIG. 3, the part borne by the front axle among the above roll-direction damping coefficients, and the rear-wheel roll damping coefficient c r is, as shown in FIG. 4, the part borne by the rear axle among the above roll-direction damping coefficients. FIGS. 2 to 4 are models (load transfer models) obtained by modeling the vehicle 1 as a pendulum. FIG. 2 is a model seen from the rear of the vehicle, FIG. 3 is a model cut along the center line of the front axle, and FIG. 4 is a model cut along the center line of the rear axle.

[0022] The roll angle acquisition unit 11 of the present embodiment uses the model of FIG. 2 to estimate (calculate) the roll angle θ by the following formula 1. In formula 1, m is the vehicle mass, h is the roll radius, I x is the roll moment of inertia, k is the vehicle roll stiffness, g is the gravitational acceleration, and all are fixed values. Note that the roll damping coefficients c f , c r are, for example, pre-mapped as constants with respect to the roll angular velocity and are obtained by applying the roll angular velocity to the map. Also, the roll angular velocity may be obtained, for example, by differentiating the estimated roll angle θ, or may be a sensor value. The vehicle roll stiffness k is the sum of the front wheel roll stiffness k f relating to the front wheels 2F and the rear wheel roll stiffness k r relating to the rear wheels 2R. Note that the roll stiffnesses k f , k r of the front and rear wheels are fixed values, and s is the Laplace operator.

[0023]

Equation

[0024] The load transfer amount estimation unit 12 estimates the load transfer amount ΔW y_f (hereinafter referred to as the front wheel side load transfer amount ΔW y_f ) between the left and right wheels of the front wheels 2F and the load transfer amount ΔW y_r (hereinafter referred to as the rear wheel side load transfer amount ΔW y_r ) between the left and right wheels of the rear wheels 2R, respectively. The front wheel side load transfer amount ΔW y_f is estimated based on the roll angle θ obtained by the roll angle acquisition unit 11, the lateral force Y f of the front wheels 2F, the front wheel roll damping coefficient c f , and the front wheel roll stiffness k f . Similarly, the rear wheel side load transfer amount ΔW y_r is estimated based on the roll angle θ obtained by the roll angle acquisition unit 11, the lateral force Y r of the rear wheels 2R, the rear wheel roll damping coefficient c r , and the rear wheel roll stiffness k r .

[0025] The lateral force Y of the front wheels 2F f is the sum of the lateral force Y of the left front wheel 2FL 1 and the lateral force Y of the right front wheel 2FR 2 (Y f = Y 1 + Y 2 ). The lateral force Y of the rear wheels 2R r is the sum of the lateral force Y of the left rear wheel 2RL 3 and the lateral force Y of the right rear wheel 2RR 4 (Y r = Y 3 + Y 4 ). The lateral forces Y of the front and rear wheels 2F, 2R f , Y r are preferably the values estimated by the load transfer amount estimation unit 12 as described later.

[0026] The load transfer amount estimation unit 12 of this embodiment estimates both the front wheel side load transfer amount ΔW y_f and the rear wheel side load transfer amount ΔW y_r . However, when the control device 10 has a function of estimating, for example, the vertical load Z 3 , Z 4 of the rear wheels 2R (and does not have a function of estimating the vertical load Z 1 , Z 2 of the front wheels 2F), the load transfer amount estimation unit 12 only needs to estimate the rear wheel side load transfer amount ΔW y_r . That is, the load transfer amount estimation unit 12 only needs to estimate at least one of the front wheel side load transfer amount ΔW y_f and the rear wheel side load transfer amount ΔW y_r .

[0027] The load transfer amount estimation unit 12 of this embodiment uses the model of FIG. 3 and estimates the front wheel side load transfer amount ΔW y_f from the following formula 2, which is a moment balance formula acting around the roll center of the front wheels 2F. Specifically, formula 2 is solved for the front wheel side load transfer amount ΔW y_f , and the front wheel side load transfer amount ΔW y_f is estimated (calculated) using the Laplace-transformed formula 3. T f in formulas 2 and 3 is the front tread, h fis the roll center height of the front wheels 2F (the height from the ground to the roll center), both of which are fixed values. Also, Z in Equation 2 1_0 and Z 2_0 are the vertical loads on the left and right front wheels 2FL, 2FR in the vehicle stop state. These values Z 1_0 , Z 2_0 may be, for example, predetermined fixed values or estimated values estimated from the stroke sensor value of the suspension or the like. Note that these values Z 1_0 , Z 2_0 do not necessarily have to be equal to each other.

[0028]

Equation

[0029] The same applies to the rear wheels 2R. That is, the load movement amount estimation unit 12 uses the model of FIG. 4 to estimate the rear wheel side load movement amount ΔW y_r from the following Equation 4, which is the moment balance equation acting around the roll center of the rear wheels 2R. Specifically, Equation 4 is solved for the rear wheel side load movement amount ΔW y_r , and the rear wheel side load movement amount ΔW y_r is estimated (calculated) using the Laplace-transformed Equation 5. T in Equations 4 and 5 r is the rear tread, h r is the roll center height of the rear wheels 2R, both of which are fixed values. Also, Z in Equation 4 3_0 and Z 4_0 are the vertical loads on the left and right rear wheels 2RL, 2RR in the vehicle stop state, which is the same as the front wheel side.

[0030]

Equation

[0031] As described above, the load movement amount estimation unit 12 of the present embodiment estimates the lateral forces Y f , Y r of the front and rear wheels 2F, 2R. Specifically, the yaw rate r detected by the yaw rate sensor 21 and the lateral acceleration A detected by the lateral acceleration sensor 22y Based on this, the lateral forces Y of the front and rear wheels 2F and 2R f , Y r are estimated. Then, when estimating the above load transfer amount ΔW y_f , ΔW y_r , the estimated lateral forces Y f , Y r are used.

[0032] The load transfer amount estimation unit 12 of the present embodiment uses the following equations 7 and 8 obtained by solving equation 6 for the lateral force Y f , Y r to estimate the lateral forces Y of the front and rear wheels 2F and 2R f , Y r respectively. Note that this estimation is performed at the same calculation cycle as the estimation of the above load transfer amount ΔW y_f , ΔW y_r .

[0033]

Equation

[0034] In equations 6 to 8, L f is the distance in the longitudinal direction between the front axle and the center of gravity G, L r is the distance in the longitudinal direction between the rear axle and the center of gravity G, and L is the wheelbase (distance between the front and rear axles), all of which are fixed values. Also, M ADD is the yaw moment due to the difference in driving and braking forces, and in the present embodiment, it is a control required value calculated by a control device different from the control device 10. However, the method for estimating the lateral forces Y f , Y r is not limited to this. For example, it may be estimated at a calculation cycle different from the estimation of the load transfer amount ΔW y_f , ΔW y_r , or another parameter may be considered instead of or in addition to the yaw moment M ADD .

[0035] Also, the load transfer amount estimation unit 12 of the present embodiment, based on the longitudinal acceleration A detected by the longitudinal acceleration sensor 23 x , estimates the load transfer amount ΔW of the longitudinal axis by the following equation 9 x (hereinafter, the longitudinal load transfer amount ΔWx is estimated. The front-rear load movement amount ΔW x is used in the estimation of the vertical load Z 1 ~Z 4 described below. Note that h in Equation 9 cg is the height of the center of gravity.

[0036]

Number

[0037] The vertical load estimation unit 13 estimates the vertical load Z y_f of each wheel 2 based on the front-wheel side load movement amount ΔW y_r and the rear-wheel side load movement amount ΔW 1 ~Z 4 estimated by the load movement amount estimation unit 12. Specifically, the vertical load Z 1_0 ~Z 4_0 of each wheel 2 in the vehicle stop state is adjusted by adding or subtracting the load movement amount caused by the running state to estimate the vertical load Z 1 ~Z 4 of each wheel 2. The vertical load estimation unit 13 of the present embodiment also uses the front-rear load movement amount ΔW x estimated by the load movement amount estimation unit 12 to estimate (calculate) each vertical load Z 1 ~Z 4 using the following Equations 10 to 13.

[0038]

Number

[0039] The vertical load estimation unit 13 of the present embodiment estimates the vertical load Z 1 ~Z 4 of each wheel 2. However, when the control device 10 has a function of estimating the vertical load Z 3 ,Z 4 of the rear wheel 2R (but does not have a function of estimating the vertical load Z 1 ,Z 2 of the front wheel 2F), the vertical load estimation unit 13 naturally estimates the vertical load Z 3 ,Z 4It is only necessary to estimate. That is, the vertical load estimation unit 13 estimates the vertical load of at least one of the wheels 2 (at least one of the front wheels 2F and the rear wheels 2R) for which the load movement amount has been estimated (ΔW y_f and ΔW y_r ), based on at least one of them).

[0040] The lateral force estimation unit 14 estimates the lateral forces Y 1 ~Z 4 of the four vertical loads Z f estimated by the vertical load estimation unit 13, the lateral force Y r of the front wheels 2F, and the lateral force Y 1 ~Y 4 of each wheel 2. In this embodiment, since the lateral forces Y f , Y r of the front and rear wheels 2F, 2R are estimated by the load movement amount estimation unit 12, the lateral force estimation unit 14 uses this estimation result when estimating the lateral forces Y 1 ~Y 4 of each wheel 2. Specifically, the lateral forces Y 1 ~Y 4 are estimated (calculated) by the following formulas 14 to 17.

[0041]

Equation

[0042] The lateral force estimation unit 14 of this embodiment estimates the lateral forces Y 1 ~Y 4 of each wheel 2. However, when the control device 10 has a function of estimating the vertical loads Z 3 , Z 4 of the rear wheels 2R (but does not have a function of estimating the vertical loads Z 1 , Z 2 of the front wheels 2F), the lateral force estimation unit 14 can estimate the lateral forces Y 3 , Y 4 of the rear wheels 2R. That is, the lateral force estimation unit 14 uses the vertical load of at least one of the wheels 2 (at least one of the front wheels 2F and the rear wheels 2R) estimated by the vertical load estimation unit 13 and the lateral force of at least one of the wheels 2 (lateral force Y f, Y r Based on this, each lateral force of at least one wheel 2 is estimated.

[0043] In addition, in this control device 10, the above-mentioned vertical load Z 1 ~Z 4 and the lateral force Y 1 ~Y 4 The processing until they are estimated is executed. The values estimated here can be used for various vehicle motion controls. For example, by using them when estimating (calculating) the driving force and braking force of each wheel 2, they can be used for controlling the actuator (driving source and braking device). Also, they can be used for controlling other actuators (AFS, ARS, active suspension) and notification devices. These controls may be implemented by the control device 10 or may be implemented by a control device different from the control device 10.

[0044] [3. Flowchart] Fig. 5 shows an example of a flowchart implemented in the above-mentioned control device 10. This flowchart is implemented at a predetermined calculation cycle, for example, when the main power supply of the vehicle 1 is on or during running. First, in step S1, information from various sensors 21 to 23 is acquired. In step S2, the roll angle θ is acquired (for example, estimated) by the roll angle acquisition unit 11. The subsequent steps S3 to S6 are implemented by the load movement amount estimation unit 12.

[0045] First, in step S3, the lateral forces Y f , Y r of the front and rear wheels 2F, 2R are estimated. Next, in step S4, the front-wheel-side load movement amount ΔW y_f is estimated. In step S5, the rear-wheel-side load movement amount ΔW y_r is estimated. In step S6, the front and rear load movement amount ΔW x is estimated. Then, in step S7, the four vertical loads Z 1 ~Z 4 are estimated by the vertical load estimation unit 13. In step S8, the four lateral forces Y 1 ~Y 4is estimated, and this flowchart is returned.

[0046] [4. Effect] According to the control device 10 described above, by using general-purpose detection means such as the yaw rate sensor 21 and the lateral acceleration sensor 22 that are standard equipment on the vehicle 1, the vertical load Z 1 ~Z 4 of at least one of the front wheels 2F and the rear wheels 2R can be estimated. In this way, in a vehicle that does not require advanced vehicle attitude control including roll, pitch, and bounce, the vertical load Z 1 ~Z 4 of at least one of the front wheels 2F and the rear wheels 2R can be estimated by a relatively simple method, so that the control configuration can be simplified, contributing to cost reduction and improved versatility. For example, in the case of the vehicle 1 where only the rear wheels 2R among the front and rear wheels 2F, 2R can independently control the left and right driving forces, if the vertical load Z 3 ,Z 4 and the lateral load transfer amount ΔW y_r of the rear wheels can be grasped, the controllability of the vehicle 1 can be improved.

[0047] In the above control device 10, the load transfer amounts ΔW y_f ,ΔW y_r of the front and rear wheels 2F, 2R are estimated using the respective lateral forces Y y of the front and rear wheels 2F, 2R estimated based on the detected yaw rate r and lateral acceleration A f ,Y r . Thereby, the estimation accuracy of the vertical load Z 1 ~Z 4 can be improved. Also, in the above control device 10, based on the longitudinal acceleration A x detected by the longitudinal acceleration sensor 23 which is the longitudinal acceleration detection means, the longitudinal load transfer amount ΔW x is estimated, and since the vertical load is estimated using this longitudinal load transfer amount ΔW x , the estimation accuracy can be further enhanced.

[0048] According to the control device 10 described above, the estimated vertical load Z 1 ~Z4 In addition to the estimated vertical load Z 1 ~Z 4 Based on this, each lateral force Y 1 ~Y 4 of the wheel 2 is also estimated. By estimating the forces in the left-right direction and the up-down direction of each wheel 2 in this way, it becomes easier to utilize them for various vehicle motion controls. For example, if it is utilized for the suppression control of the spin behavior, which is one of the vehicle motion controls, the driving force of each wheel 2 can be appropriately set, and the lateral slip of the tire can be effectively suppressed.

[0049] [5. Others] The configuration of the control device 10 described above is an example and is not limited to the above. The formulas 1, 3, 5, 7 to 16 used by the above control device 10 for estimation are examples and are not limited to the above formulas. For example, in the above vertical load estimation unit 13, when estimating the vertical load Z 1 ~Z 4 the front-rear load transfer amount ΔW x estimated by the load transfer amount estimation unit 12 is used, but the front-rear load transfer amount may be omitted or a preset (predicted) value may be adopted.

[0050] Also, the configuration of the vehicle 1 to which the control device 10 is applied is an example and is not limited to the above. For example, when the vehicle 1 is equipped with a lateral slip prevention device (ASC; Active Stability Control), the ASC may be activated according to the information estimated by the above control device 10. Also, the type of actuator controlled using the estimation result of the control device 10 mounted on the above vehicle 1 is not particularly limited.

Explanation of Signs

[0051] 1 Vehicle 2 Wheel 2F Front wheel 2FL Left front wheel (front wheel, wheel) 2FR Right front wheel (front wheel, wheel) 2R Rear wheel 2RL Left rear wheel (rear wheel, wheel) 2RR Right rear wheel (rear wheel, wheel) 10 Control device 11 Roll angle acquisition unit 12 Load movement amount estimation unit 13 Vertical load estimation unit 14 Lateral force estimation unit 21 Yaw rate sensor 22 Lateral acceleration sensor 23 Longitudinal acceleration sensor A x Longitudinal acceleration A y Lateral acceleration c Vehicle roll damping coefficient c f Front wheel roll damping coefficient c r Rear wheel roll damping coefficient G Center of gravity g Gravitational acceleration h Roll radius h f Front wheel roll center height h r Rear wheel roll center height I x Roll moment of inertia k Vehicle roll stiffness k f Front wheel roll stiffness k r Rear wheel roll stiffness L Wheelbase (distance between front and rear axles) L f Distance in the longitudinal direction between the front axle and the center of gravity L r Distance in the longitudinal direction between the rear axle and the center of gravity m Vehicle mass M ADD Yaw moment due to difference in driving and braking forces r Yaw rate T f Front tread T r Rear tread ΔW x Longitudinal and lateral load movement amount (load movement amount between front and rear axles) ΔW y_f Lateral load movement amount on the front wheel side (load movement amount between the left and right wheels of the front wheel) ΔW y_rRear wheel side load transfer amount (load transfer amount between the left and right wheels of the rear wheel) Y 1 Lateral force of the left front wheel Y 2 Lateral force of the right front wheel Y 3 Lateral force of the left rear wheel Y 4 Lateral force of the right rear wheel Y f Lateral force of the front wheels Y r Lateral force of the rear wheels Z 1 Vertical load of the left front wheel Z 2 Vertical load of the right front wheel Z 3 Vertical load of the left rear wheel Z 4 Vertical load of the right rear wheel θ Roll angle

Claims

1. In a control device for a vehicle provided with a yaw rate detection means for detecting a yaw rate of the vehicle and a lateral acceleration detection means for detecting a lateral acceleration of the vehicle, a roll angle acquisition unit that acquires a roll angle of the vehicle; a load transfer amount estimation unit that estimates at least one of a load transfer amount between the left and right wheels of the front wheels based on the acquired roll angle, the lateral force of the front wheels, the front wheel roll damping coefficient related to the front wheels, and the front wheel roll stiffness related to the front wheels, and a load transfer amount between the left and right wheels of the rear wheels based on the acquired roll angle, the lateral force of the rear wheels, the rear wheel roll damping coefficient related to the rear wheels, and the rear wheel roll stiffness related to the rear wheels; a vertical load estimation unit that estimates the vertical load of at least one of the front wheels and the rear wheels for which the load transfer amount has been estimated based on the estimated load transfer amount, characterized in that it is a control device for a vehicle.

2. When estimating the load transfer amount, the load transfer amount estimation unit uses the lateral force of at least one of the wheels estimated based on the detected yaw rate and the detected lateral acceleration. The control device for a vehicle according to claim 1, characterized in that.

3. The vehicle is provided with a longitudinal acceleration detection means for detecting a longitudinal acceleration of the vehicle, the load transfer amount estimation unit estimates a load transfer amount of the longitudinal axis based on the detected longitudinal acceleration, and the vertical load estimation unit uses the estimated load transfer amount of the longitudinal axis when estimating the vertical load. The control device for a vehicle according to claim 1 or 2, characterized in that.

4. A lateral force estimation unit that estimates the lateral force of each of the at least one of the wheels based on the vertical load of the at least one of the wheels estimated by the vertical load estimation unit and the lateral force of the at least one of the wheels. The control device for a vehicle according to claim 1 or 2, characterized in that.

5. A lateral force estimation unit that estimates the lateral force of each of the at least one of the wheels based on the vertical load of the at least one of the wheels estimated by the vertical load estimation unit and the lateral force of the at least one of the wheels. The control device for a vehicle according to claim 3, characterized in that.

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