Vehicle control device and vehicle control program

Abstract

To improve vehicle handling stability and ride comfort during vehicle turns. [Solution] The control device 50 is applied to a vehicle 10 equipped with an actuator that can adjust the roll motion of the vehicle 10. The control device 50 controls the roll motion of the vehicle 10 by operating the actuator. The control device 50 acquires front roll angle information and rear roll angle information based on the torsional rigidity of the components of the vehicle 10 located between the front wheels FL, FR and the rear wheels RR, RL. Based on the front roll angle information and rear roll angle information, the control device 50 derives a control amount for the actuator and operates the actuator based on the control amount.

Description

[Technical Field]

[0001] This invention relates to a vehicle control device and a vehicle control program. [Background technology]

[0002] The vehicle control device disclosed in Patent Document 1 increases the ratio of the roll stiffness coefficient of the rear of the vehicle to the roll stiffness coefficient of the front of the vehicle when the roll component of the vehicle vibration is below a predetermined value, compared to when the roll component is greater than a predetermined value. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-40195 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The objective of this invention is to improve the handling stability and ride comfort of a vehicle when it is turning. [Means for solving the problem]

[0005] A vehicle control device for solving the above problems is applied to a vehicle equipped with an actuator capable of adjusting the roll motion of the vehicle. The vehicle control device controls the roll motion of the vehicle by operating the actuator. The vehicle control device includes an acquisition unit that acquires front roll angle information, which includes at least one of the roll angle and roll angular velocity of the front of the vehicle body, and rear roll angle information, which includes at least one of the roll angle and roll angular velocity of the rear of the vehicle body, based on the torsional rigidity of the vehicle components located between the front and rear wheels of the vehicle, and an output unit that derives a control amount for the actuator based on the front roll angle information and the rear roll angle information.

[0006] A vehicle control program for solving the above problems is a program that controls the roll motion of a vehicle by operating an actuator that adjusts the roll motion of the vehicle. The vehicle control program causes a processing circuit to perform the following processes: acquire front roll angle information, which includes at least one of the roll angle and roll angular velocity of the front of the vehicle body, and rear roll angle information, which includes at least one of the roll angle and roll angular velocity of the rear of the vehicle body, based on the torsional rigidity of the vehicle components located between the front and rear wheels of the vehicle; derive a control amount for the actuator based on the front roll angle information and the rear roll angle information; and control the actuator based on the control amount. [Effects of the Invention]

[0007] To improve vehicle handling stability and ride comfort during vehicle turns. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing a vehicle equipped with the control device of the embodiment. [Figure 2] Figure 2 is a schematic perspective view of the vehicle shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing a cross-section of the front of the vehicle shown in Figure 1. [Figure 4] Figure 4 is a schematic diagram showing a cross-section of the rear of the vehicle shown in Figure 1. [Figure 5] Figure 5 is a block diagram showing a control model, which is an example of a roll motion model for the vehicle in Figure 1. [Figure 6] Figure 6 is a block diagram showing the functional configuration of the control device in Figure 1. [Figure 7] Figure 7 is a block diagram showing the functional configuration of the correction control amount derivation unit in Figure 6. [Figure 8] Figure 8 is a flowchart showing the processes performed by the CPU of the control device shown in Figure 1. [Figure 9] Figure 9 shows the results of a simulation illustrating the change in roll angular velocity. [Figure 10] Figure 10 shows the results of a simulation illustrating the change in yaw rate. [Figure 11] Figures 11(a) to 11(c) are timing charts showing the changes in various parameters during the turning of the vehicle in Figure 1. [Modes for carrying out the invention]

[0009] An embodiment of a vehicle control device and a vehicle control program will be described with reference to Figures 1 to 11. <Overall vehicle configuration> Figures 1 and 2 illustrate a vehicle 10 equipped with a vehicle control device 50. The vehicle 10 comprises a plurality of wheels, a body 12, and a steering wheel 13. The plurality of wheels include the left front wheel FL, the right front wheel FR, the left rear wheel RL, and the right rear wheel RR. The plurality of front wheels FL and FR are steering wheels that are turned by the operation of the steering wheel 13 by the driver of the vehicle 10.

[0010] The front axle 11F shown in Figure 1 is a virtual straight line that extends in the vehicle width direction Y and passes through the center of the vehicle's longitudinal direction X at the position of the front wheel. Similarly, the rear axle 11R shown in Figure 1 is a virtual straight line that extends in the vehicle width direction Y and passes through the center of the vehicle's longitudinal direction X at the position of the rear wheel.

[0011] Vehicle 10 is equipped with multiple sensors. The multiple sensors 21, 22, 23, and 24 include, for example, a steering angle sensor, a longitudinal acceleration sensor, a lateral acceleration sensor, a yaw rate sensor, and multiple wheel speed sensors. The steering angle sensor detects the steering angle STR of the steering wheel 13. The longitudinal acceleration sensor detects the longitudinal acceleration GX of vehicle 10. The lateral acceleration sensor detects the lateral acceleration GY of vehicle 10. The yaw rate sensor detects the yaw rate γ of vehicle 10. The wheel speed sensors detect the wheel speed VW of the corresponding wheels FL, FR, RL, and RR. The vehicle speed V of vehicle 10 is derived from the wheel speeds VW of the multiple wheels FL, FR, RL, and RR.

[0012] The vehicle 10 includes a pair of front wheel suspensions 31FL, 31FR positioned on both sides in the vehicle width direction Y, and a pair of rear wheel suspensions 31RL, 31RR positioned on both sides in the vehicle width direction Y. The front wheel suspension 31FL is interposed between the left front wheel FL and the vehicle body 12, and the front wheel suspension 31FR is interposed between the right front wheel FR and the vehicle body 12. The rear wheel suspension 31RL is interposed between the left rear wheel RL and the vehicle body 12, and the rear wheel suspension 31RR is interposed between the right rear wheel RR and the vehicle body 12.

[0013] Each of the multiple front suspensions 31FL, 31FR and rear suspensions 31RL, 31RR has a damper, and is configured to allow for variable damping force. For example, the damping force of the dampers of the suspensions 31FL, 31FR, 31RL, and 31RR can be varied by instructions from the vehicle control device 50. When the damping force of the damper is changed, the roll motion of the vehicle 10 during cornering changes. In this respect, the multiple suspensions 31FL, 31FR, 31RL, and 31RR correspond to "actuators" that can adjust the roll motion of the vehicle 10. Hereafter, the damping force of the dampers of the suspensions 31FL, 31FR, 31RL, and 31RR will be simply referred to as "damping force of suspensions 31FL, 31FR, 31RL, and 31RR".

[0014] <Roll characteristics of a vehicle during turns> Referring to Figures 2 to 4, the roll motion of the vehicle 10 when it turns will be explained. The plane perpendicular to the vehicle's longitudinal direction X is the "YZ plane". The vertical direction Z shown in Figure 2 is perpendicular to the road surface. Figure 2 shows the front YZ plane Pyzf, which includes the front axle 11F, and the rear YZ plane Pyzr, which includes the rear axle 11R. In this embodiment, the rotation angle around the roll center 41 on the front YZ plane Pyzf is the front roll angle θ xf Therefore, the rotation angle around the roll center 41 on the rear YZ plane Pyzr is the rear roll angle θ. xr That is the case.

[0015] When vehicle 10 turns, as shown by the arrow AR in Figure 2, a roll motion occurs in vehicle 10. In particular, in the initial stages of vehicle 10's turn, a discrepancy may occur between the roll motion of the front part 12F of vehicle 10 shown in Figure 3 and the roll motion of the rear part 12R of vehicle 10 shown in Figure 4.

[0016] Specifically, as the vehicle moves, multiple front wheels FL and FR steer, causing the vehicle 10 to begin turning. This results in a roll moment I at the front of the vehicle 12F. rf The addition of this causes roll motion at the front 12F of the vehicle body. Therefore, the front roll angle θ is the roll angle of the front 12F of the vehicle body. xf This changes. When roll motion occurs at the front of the vehicle 12F, a roll moment I also occurs at the rear of the vehicle 12R. rr This is added. As a result, roll motion occurs even at the rear 12R of the vehicle body, and the rear roll angle θ of the rear 12R of the vehicle body xr This changes. If there is a large discrepancy between the roll motion of the front part 12F of the vehicle body and the roll motion of the rear part 12R of the vehicle body, the driver is likely to feel discomfort in the handling and ride comfort of the vehicle 10.

[0017] A discrepancy between the roll motion of the front 12F and the roll motion of the rear 12R of the vehicle body means that twisting is occurring in the components of the vehicle 10 located between the front wheels FL, FR and the rear wheels RL, RR. The inventors of this case hypothesized that twisting occurs in the intermediate portion of the vehicle body 12, which is the part between the front axle 11F and the rear axle 11R, and that the reaction force moment due to the torsional rigidity of this intermediate portion affects the roll motion of the front 12F and the rear 12R of the vehicle body. The inventors hypothesized that by individually adjusting the damping force of multiple suspensions 31FL, 31FR, 31RL, and 31RR, taking into account the torsional rigidity of the intermediate portion, the discrepancy between the roll motion of the front 12F and the roll motion of the rear 12R of the vehicle body during cornering can be reduced.

[0018] <Vehicle Roll Motion Model> FIG. 3 illustrates a schematic diagram when the vehicle 10 is cut along a front YZ plane Pyzf. FIG. 4 illustrates a schematic diagram when the vehicle 10 is cut along a rear YZ plane Pyzr. In FIG. 3 and FIG. 4, "I xf " is the roll moment of inertia of the roll motion around the roll center 41 in the front YZ plane Pyzf. "I xr " is the roll moment of inertia of the roll motion around the roll center 41 in the rear YZ plane Pyzr. "w f " is the tread length at the vehicle body front portion 12F, and "w r " is the tread length at the vehicle body rear portion 12R. "K sf " is the spring constant of the front wheel suspensions 31FL, 31FR, and "K sr " is the spring constant of the rear wheel suspensions 31RL, 31RR. "C sf " is the damping coefficient of the damper of the front wheel suspensions 31FL, 31FR, and "C sr " is the damping coefficient of the damper of the rear wheel suspensions 31RL, 31RR. "h rf " is the height of the roll center 41 at the front YZ plane Pyzf, and "h rr " is the height of the roll center 41 at the rear YZ plane Pyzr. "h cg " is the height of the center of gravity of the vehicle 10. "ΔF czfl " is the correction amount of the vertical damping force of the front wheel suspension 31FL, and "ΔF czfr " is the correction amount of the vertical damping force of the front wheel suspension 31FR. "ΔF czrl " is the correction amount of the vertical damping force of the rear wheel suspension 31RL, and "ΔF czrr " is the correction amount of the vertical damping force of the rear wheel suspension 31RR. "F yf " is the cornering force acting on the front wheels FL, FR, and "F yr " is the cornering force acting on the rear wheels RL, RR.

[0019] As described above, taking into account the torsional rigidity of the middle section of the vehicle body 12, the equations for roll motion at the front axle 11F (D1) and the equations for roll motion at the rear axle 11R (D2) are as follows.

[0020]

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[0021] According to the equation (D1) for roll motion at the position of the front axle 11F described above, the roll angular acceleration of the front part 12F of the vehicle body is determined by the rear roll angle θ. xr and rear roll angular velocity dθ xr It can be seen that / dt is reflected. Similarly, according to the equation for roll motion at the position of the rear axle 11R above (D2), the roll angular acceleration of the rear of the vehicle 12R is equal to the front roll angle θ xf and front roll angular velocity dθ xf This shows that / dt is reflected.

[0022] Next, the basic equations (D3) and (D4) for the planar motion of vehicle 10 using the two-wheeled model of vehicle 10 are as follows. In the following basic equations (D3) and (D4), "β" is the sideslip angle of the center of gravity of vehicle 10, and "γ" is the yaw rate of the center of gravity of vehicle 10. Also, "I z " represents the yawing moment of inertia of vehicle 10.

[0023]

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[0024]

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[0025]

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[0026] Furthermore, according to the above multiple relationships, the equation of motion (D9) for the vehicle slip angle β can be expressed as follows. The equation of motion (D10) for the yaw rate γ can be expressed as follows. According to the said equation of motion (D10), the front roll angle θ xf and rear roll angle θ xr It is clear that if at least one of these changes, the rate of change of yaw rate γ changes.

[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034] Figure 5 illustrates an example of a control model 100 that uses the above-described roll motion model to derive correction amounts for multiple suspensions 31FL, 31FR, 31RL, and 31RR. This control model 100 is a model of a state feedback control structure for a linear model. In this embodiment, an optimal regulator is used as a means for deriving the control law of state feedback control. The evaluation function of the optimal regulator can be expressed by the following relation (D22). Then, "P" can be derived using the Riccati equation (D23) shown below. Furthermore, using this "P", the state feedback gain K shown by relation (D24) can be derived.s This can be derived.

[0035]

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[0036]

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[0037] Furthermore, while the control device 50 adjusts the damping force of multiple suspensions 31FL, 31FR, 31RL, and 31RR, the front wheel steering angle δ f and rear wheel steering angle δ r If this is not adjusted, in the matrix R represented by the determinant (D26), "r1" to "r4" will be set to 1, while "r5" and "r6" will be set to extremely large values.

[0038] Furthermore, when deriving the correction amounts for multiple suspensions 31FL, 31FR, 31RL, and 31RR using the control model 100, the input u0 is created based on the matrix u shown in the above relation (D17). That is, "ΔF czfl "ΔF czfr "ΔF czrl " and "ΔF czrr 0 (zero) is set to ". On the other hand, "δ f The current front wheel steering angle is set in "δ r The current rear wheel steering angle is set in this field. When this input u0 is input to the control model 100, "Δu" can be obtained as an output. "Δu" is a matrix that includes a correction amount to make the difference between the roll angular velocity of the front part 12F of the vehicle body and the roll angular velocity of the rear part 12R of the vehicle body 0 (zero). In this embodiment, the front wheel steering angle δ fand rear wheel steering angle δ r Since no adjustment is made, in matrix Δu, "Δδ f " and "Δδ f This value is infinitesimally small, practically equivalent to 0 (zero).

[0039] <Vehicle control system> The vehicle control device 50 will now be described. Hereafter, the vehicle control device 50 will be simply referred to as "control device 50".

[0040] As shown in Figure 1, the control device 50 is an electronic control device that controls the damping force of multiple suspensions 31FL, 31FR, 31RL, and 31RR. In this case, the control device 50 has a CPU 51, a first memory 52, and a second memory 53. The first memory 52 stores a vehicle control program that derives the control amounts for the multiple suspensions 31FL, 31FR, 31RL, and 31RR that adjust the roll motion of the vehicle 10. The second memory 53 stores the calculation results of the CPU 51. By executing the vehicle control program in the first memory 52, the CPU 51 can adjust the damping force of the multiple suspensions 31FL, 31FR, 31RL, and 31RR. In this respect, the CPU 51 corresponds to a "processing circuit" that executes the vehicle control program.

[0041] The control device 50 receives vehicle state values, which include the detection values ​​from the multiple sensors 21 to 24 and calculated values ​​derived based on those detection values. The detection values ​​include steering angle STR, longitudinal acceleration GX, lateral acceleration GY, and yaw rate γ. The vehicle state values ​​include vehicle speed V and front wheel steering angle δ. f and rear wheel steering angle δ r Includes front wheel steering angle δ. f This is the representative steering angle of the front wheels, which can be derived from the steering angles of the front wheels FL and FR. Rear wheel steering angle δ rThis is a representative steering angle of the rear wheels that can be derived from the steering angles of the rear wheels RL and RR. Based on these various input values ​​to the control device 50, the control device 50 individually derives control amounts for multiple suspensions 31FL, 31FR, 31RL, and 31RR. Then, the control device 50 operates the multiple suspensions 31FL, 31FR, 31RL, and 31RR based on these control amounts.

[0042] <Functional Configuration of Control Device> The functional configuration of the control device 50 will be described with reference to Figures 6 and 7. As shown in Figure 6, the control device 50 functions as a plurality of functional units when the CPU 51 executes the vehicle control program in the first memory 52. ​​The plurality of functional units include a damping force correction amount derivation unit M10, a stroke direction determination unit M20, a correction control amount derivation unit M30, a reference control amount setting unit M40, a command control amount derivation unit M50, and a command unit M60.

[0043] The damping force correction amount derivation unit M10 uses the control model 100 shown in Figure 5 to calculate the damping force correction amount ΔF for multiple suspensions 31FL, 31FR, 31RL, and 31RR. czij The following is derived: For example, the correction amount ΔF when "i" is set to "f" and "j" is set to "l". czfl This represents the damping force correction amount for the front wheel suspension 31FL. The same applies to the suspensions for the other wheels 31FR, 31RL, and 31RR. The damping force correction amount derivation unit M10 takes the front wheel steering angle δ as input information. f , rear wheel steering angle δ r The vehicle speed V is also input. Then, the damping force correction amount derivation unit M10 calculates a value corresponding to this input information for the damping force correction amount ΔF of the multiple suspensions 31FL, 31FR, 31RL, and 31RR. czij This is derived as follows.

[0044] The damping force correction amount derivation unit M10 includes a subtraction unit M11, an acquisition unit M12, and a multiplication unit M13. The subtraction unit M11 derives the "u" shown in the above relation (D17) by subtracting "Δu" from "u0". "Δu" is the output of the multiplication unit M13.

[0045] The acquisition unit M12 derives the state variable "x" shown in the above relational expression (D16) based on "u" derived by the subtraction unit M11. The multiplication unit M13 derives "Δu" using the state feedback gain Ks shown in the above relational equation (D24). This "Δu" is the damping force correction amount ΔF of the multiple suspensions 31FL, 31FR, 31RL, and 31RR. czij It is a vector that contains [the specified value].

[0046] The stroke direction determination unit M20 determines the stroke direction of multiple suspensions 31FL, 31FR, 31RL, and 31RR. Here, "stroke direction" refers to whether the suspension has extended or contracted.

[0047] For example, the stroke direction determination unit M20 estimates the stroke velocities of multiple suspensions 31FL, 31FR, 31RL, and 31RR based on the longitudinal acceleration GX and lateral acceleration GY of the vehicle 10. Then, the stroke direction determination unit M20 estimates the stroke direction of the multiple suspensions 31FL, 31FR, 31RL, and 31RR using the positive or negative value of the stroke velocities. For example, when the vehicle 10 is decelerating, the vehicle 10 pitches, so the stroke velocities of the front suspensions 31FL and 31FR become negative values, while the stroke velocities of the rear suspensions 31RL and 31RR become positive values. The stroke direction determination unit M20 determines that the suspension with a negative stroke velocity is contracting. The stroke direction determination unit M20 determines that the suspension with a positive stroke velocity is extending.

[0048] The correction control amount derivation unit M30 calculates the correction amount ΔF of the damping force of multiple suspensions 31FL, 31FR, 31RL, and 31RR. czijand the stroke direction, a corrected control amount ΔC, which is a correction amount for the control amounts of the plurality of suspensions 31FL, 31FR, 31RL, 31RR ij is derived. Details of the corrected control amount derivation unit M30 will be described later. Note that the corrected control amount ΔC in which "f" is set to "i" and "l" is set to "j" fl represents the corrected control amount for the front wheel suspension 31FL. The same applies to the corrected control amounts for the other wheel suspensions 31FR, 31RL, 31RR.

[0049] The reference control amount setting unit M40 sets a reference control amount CB, which is a reference value for the control amounts of the plurality of suspensions 31FL, 31FR, 31RL, 31RR ij . The reference control amount setting unit M40 sets the appropriate value of the control amount when the vehicle 10 is traveling straight ahead as the reference control amount CB ij . For example, a fixed value determined by the specifications of the vehicle 10 may be set as the reference control amount CB ij . Note that the reference control amount CB in which "f" is set to "i" and "l" is set to "j" fl represents the reference control amount of the front wheel suspension 31FL. The same applies to the reference control amounts of the other wheel suspensions 31FR, 31RL, 31RR.

[0050] The command control amount derivation unit M50 derives a command control amount C, which is a command value for the control amounts of the plurality of suspensions 31FL, 31FR, 31RL, 31RR ij . Specifically, the command control amount derivation unit M50 sets the sum of the reference control amount CB ij and the corrected control amount ΔC ij as the command control amount C ij . Therefore, when the corrected control amount ΔC ij is a positive value, a value larger than the reference control amount CB ij is derived as the command control amount C ij . On the other hand, when the corrected control amount ΔC ij is a negative value, a value smaller than the reference control amount CB ij is derived as the command control amount C ijis derived as. Note that "f" is set to "i", and the command control amount C with "l" set to "j" fl represents the command control amount of the front wheel suspension 31FL. The same applies to the command control amounts of the other wheel suspensions 31FR, 31RL, and 31RR.

[0051] In the present embodiment, an example of the "derivation unit" that derives the command control amounts C of the plurality of suspensions 31FL, 31FR, 31RL, 31RR is configured by the multiplication unit M13 of the damping force correction amount derivation unit M10, the correction control amount derivation unit M30, and the command control amount derivation unit M50. ij is derived, and an example of the "derivation unit" is configured.

[0052] The command unit M60 operates the plurality of suspensions 31FL, 31FR, 31RL, 31RR based on the plurality of command control amounts C. ij Specifically, the command unit M60 operates the front wheel suspension 31FL based on the command control amount C. fl The command unit M60 operates the front wheel suspension 31FR based on the command control amount C. fr The command unit M60 operates the rear wheel suspension 31RL based on the command control amount C. rl The command unit M60 operates the rear wheel suspension 31RR based on the command control amount C. rr The command unit M60 operates the rear wheel suspension 31RR based on the command control amount C.

[0053] <Detailed Functional Configuration of Correction Control Amount Derivation Unit> The correction control amount derivation unit M30 will be described with reference to FIG. 7. The correction control amount derivation unit M30 includes a sign inversion unit M31, an extension correction control amount derivation unit M32, a contraction correction control amount derivation unit M33, and a selection unit M34.

[0054] The sign inversion unit M31 inverts the positive / negative sign of the correction amount ΔF. czij Specifically, the sign inversion unit M31 inverts the positive / negative sign of the correction amount ΔF. czij The product of the correction amount ΔF and "-1" is derived as the inverted correction amount ΔFA. czij is derived as.

[0055] The stretch correction control amount derivation unit M32 uses the stretch map MP1 to determine the inversion correction amount ΔFA czij The corresponding value is the extension correction control amount ΔC1 ij The extension map MP1 is the correction amount ΔF when extending the suspension. cz This is a map showing the relationship between the extension correction control amount ΔC. The extension correction control amount derivation unit M32 derives the inversion correction amount ΔFA from the extension map MP1. czij A corresponding value is derived. Then, the extension correction control amount derivation unit M32 uses the derived value to determine the extension correction control amount ΔC1 ij Set to this.

[0056] The contraction correction control amount derivation unit M33 uses the contraction map MP2 to calculate the correction amount ΔF czij The corresponding value is the contraction correction control amount ΔC2 ij The following is derived: The compression map MP2 is the correction amount ΔF when compressing the suspension. cz This is a map showing the relationship between the correction control amount ΔC and the contraction correction control amount. The contraction correction control amount derivation unit M33 derives the correction amount ΔF from the contraction map MP2. czij A corresponding value is derived. Then, the contraction correction control amount derivation unit M33 uses the derived value to determine the contraction correction control amount ΔC2 ij Set to this.

[0057] The selection unit M34 determines the extension correction control amount ΔC1 based on the determination result of the stroke direction determination unit M20. ij and contraction correction control amount ΔC2 ij One of them is the corrected control amount ΔC ij Select as follows. For example, if it is determined that the front suspension 31FL is extended, the selection unit M34 selects the extension correction control amount ΔC1 fl Correction control amount ΔC fl Select as follows. Also, for example, if it is determined that the rear suspension 31RR is compressed, the selection unit M34 selects the compression correction control amount ΔC2 rr Correction control amount ΔC rr Select it as such.

[0058] <Roll motion adjustment process> Figure 8 illustrates the roll motion adjustment process that the CPU 51 of the control device 50 repeatedly executes at predetermined control cycles to control the roll motion of the vehicle 10. The roll motion adjustment process is executed when the CPU 51 executes the vehicle control program in the first memory 52.

[0059] In step S11, the CPU 51 acquires detection values ​​from various sensors 21-24. For example, the CPU 51 acquires steering angle STR, longitudinal acceleration GX, lateral acceleration GY, and yaw rate γ. In the next step S13, the CPU 51 derives various vehicle state quantities. For example, the CPU 51 derives vehicle speed V and front wheel steering angle δ. f and rear wheel steering angle δ r Derive the following.

[0060] In the subsequent step S15, the CPU 51 acquires front roll angle information and rear roll angle information. At this time, the CPU 51 acquires all state variable information defined by the above relational expression (D16) based on the control model 100. In the control device 50, the CPU 51 acquires the front roll angle θ as front roll angle information. xf and front roll angular velocity dθ xf The / dt is obtained. Also, CPU 51 obtains the rear roll angle θ as rear roll angle information. xr and rear roll angular velocity dθ xr The / dt value is obtained. In this respect, the process in step S15 corresponds to the process of causing the CPU 51 to obtain the front roll angle information and the rear roll angle information.

[0061] In the next step S17, the CPU 51 controls the command control amount C of the multiple suspensions 31FL, 31FR, 31RL, and 31RR based on all state information, including the front roll angle information and rear roll angle information acquired in step S15. fl ,C fr ,C rl ,C rr This derives the following. In this regard, the process in step S17 determines the command control amount C of the suspensions 31FL, 31FR, 31RL, and 31RR based on the front roll angle information and the rear roll angle information. ijThis corresponds to the process of deriving the result to CPU51.

[0062] Then, in step S19, the CPU 51 controls the multiple command control quantities C derived in step S17. fl ,C fr ,C rl ,C rr Based on this, multiple suspensions 31FL, 31FR, 31RL, and 31RR are controlled. In this respect, the processing in step S19 controls the command control amount C ij Based on this, the process involves having the CPU 51 control the suspensions 31FL, 31FR, 31RL, and 31RR. After that, the CPU 51 terminates the current roll motion adjustment process.

[0063] <Operation in this embodiment> Figures 9 and 10 show the front roll angular velocity dθ when the vehicle 10 is turned while the vehicle speed V is maintained at a predetermined speed. xf / dt and rear roll angular velocity dθ xr The simulation results when the above control is implemented so that the deviation from / dt is 0 (zero) are shown in the figure. Here, the case when the above control is not implemented is described as a comparative example. In Figure 9, the front roll angular velocity dθ in this embodiment is shown. xf The progression of / dt is shown by a solid line, and the rear roll angular velocity dθ in this embodiment is shown. xr The progression of / dt is shown by the dashed line. Also, the front roll angular velocity dθ in the comparative example is shown. xf The progression of / dt is shown by a dashed line, and the rear roll angular velocity dθ in the comparative example is shown. xr The transition of / dt is shown by a dashed line. In Figure 10, the transition of yaw rate γ in this embodiment is shown by a solid line, while the transition of yaw rate γ in the comparative example is shown by a dashed line.

[0064] As shown in Figure 9, simulations indicate that when the above control is implemented, the front roll angular velocity dθ is higher compared to the comparative example where no control is implemented. xf / dt and rear roll angular velocity dθ xrThe maximum value of / dt becomes smaller. Furthermore, the front roll angular velocity dθ xf Maximum value of / dt and rear roll angular velocity dθ xr The deviation from the maximum value of / dt is smaller compared to the comparative example.

[0065] Furthermore, as shown in Figure 10, simulations indicate that the yaw rate γ of the vehicle 10 at the initial stage of turning increases when the above-described control is implemented, compared to a comparative example where no control is implemented.

[0066] In other words, according to the simulation results, the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr By suppressing the divergence between / dt and the roll motion, the divergence between the front 12F and rear 12R of the vehicle body is reduced during the initial phase of vehicle turning. As a result, improvements in the handling stability and ride comfort of the vehicle 10 are expected. In addition, since the yaw rate γ of the vehicle 10 becomes larger during the initial phase of vehicle turning, improvements in the responsiveness of the vehicle 10 to the driver's steering input are expected during the initial phase of vehicle turning.

[0067] Figure 11 shows the front roll angular velocity dθ when the vehicle 10 is turned while the vehicle speed V is maintained at a predetermined speed. xf / dt and rear roll angular velocity dθ xr The figure shows the actual vehicle data when the above control is implemented so that the deviation from / dt is 0 (zero). Figure 11(a) shows the change in steering angle STR. Figure 11(b) shows the front roll angular velocity dθ in this embodiment. xf The progression of / dt is shown by a dashed line, and the rear roll angular velocity dθ in this embodiment is shown. xr The progression of / dt is shown by the solid line. Also, the front roll angular velocity dθ in the comparative example is shown. xf The progression of / dt is shown by the dashed line, and the rear roll angular velocity dθ in the comparative example is shown. xr The transition of / dt is shown by a dashed line. In Figure 11(c), the transition of yaw rate γ in this embodiment is shown by a solid line, while the transition of yaw rate γ in the comparative example is shown by a dashed line.

[0068] As shown in Figure 11(b), when the above control is implemented in the actual vehicle, the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr The maximum value of / dt becomes smaller. Furthermore, the front roll angular velocity dθ xf / dt, maximum value, and rear roll angular velocity dθ xr The deviation from the maximum value of / dt is smaller compared to the comparative example.

[0069] Furthermore, as shown in Figure 11(c), when the above control is implemented in the actual vehicle, the time it takes for the yaw rate γ to converge to a steady value corresponding to the steering angle STR is shortened once the steering angle STR is maintained at a constant value.

[0070] <Effects of this embodiment> (1) The control device 50 acquires front roll angle information and rear roll angle information based on the torsional rigidity of the middle portion of the vehicle body 12. Based on the front roll angle information and rear roll angle information, the command control amount C of the multiple suspensions 31FL, 31FR, 31RL, and 31RR is controlled. fl ,C fr ,C rl ,C rr The command control quantity C is derived. fl ,C fr ,C rl ,C rr Based on this, multiple suspensions 31FL, 31FR, 31RL, and 31RR are controlled. This allows the control device 50 to adjust the damping force of the multiple suspensions 31FL, 31FR, 31RL, and 31RR, taking into account the torsional rigidity mentioned above. In other words, when the vehicle 10 is turning, the control device 50 controls the front roll angle θ xf and front roll angular velocity dθ xf Front roll angle information including / dt and rear roll angle θ xr and rear roll angular velocity dθ xr The rear roll angle information, including / dt, can be appropriately controlled. Therefore, the control device 50 can improve the handling stability and ride comfort of the vehicle 10.

[0071] (2) In the control device 50, the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr Command control quantity C that can suppress deviation from / dt fl ,C fr ,C rl ,C rr This is derived. And these command control quantities C fl ,C fr ,C rl ,C rr Based on this, multiple suspensions 31FL, 31FR, 31RL, and 31RR are controlled. This controls the front roll angular velocity dθ when the vehicle 10 is turning. xf / dt and rear roll angular velocity dθ xr This reduces the likelihood of a discrepancy occurring between / dt and the value. As a result, it is possible to reduce the discomfort experienced by the driver of the vehicle 10 due to the discrepancy in roll motion between the front 12F and the rear 12R of the vehicle body during vehicle turning.

[0072] (3) The control model 100 described above has a front wheel steering angle δ f and rear wheel steering angle δ r This model shows the relationship between steering angle information, vehicle speed V, front roll angle information, and rear roll angle information, and is a roll motion model created considering the torsional rigidity of the middle part of the vehicle body 12. The control device 50 has such a control model 100. Based on this control model 100, values ​​corresponding to the front wheel steering angle δf, rear wheel steering angle δr, and vehicle speed V are derived as front roll angle information and rear roll angle information. As a result, the control device 50 can quickly reflect the front wheel steering angle δf, rear wheel steering angle δr, and vehicle speed V at that time in the control of the multiple suspensions 31FL, 31FR, 31RL, and 31RR.

[0073] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0074] The control model 100 described above is a roll motion model created considering the torsional rigidity of the middle section of the vehicle body 12. When the vehicle turns, it is possible that components of the vehicle 10 other than the vehicle body 12 may twist. For example, structural members such as suspension members may twist. Therefore, as a control model, a control model created considering the torsional rigidity of structural members located between the front wheels FL, FR and the rear wheels RL, RR may be adopted.

[0075] The control model may be a pre-trained model created using machine learning. The control device does not need to use a roll motion model such as control model 100, as long as it can acquire front roll angle information and rear roll angle information while taking into account the torsional rigidity of the middle section of the vehicle body 12.

[0076] The control device controls the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr The control amount of multiple suspensions 31FL, 31FR, 31RL, and 31RR may be corrected to suppress only one of / dt. In this case, the control device uses the front roll angular velocity dθ instead of the output equation that serves as the control target defined in equation (D20) above. xf / dt and rear roll angular velocity dθ xr By using an output equation consisting only of the elements to be suppressed from / dt, the correction control amounts for multiple suspensions 31FL, 31FR, 31RL, and 31RR can be derived.

[0077] • In the above embodiment, the control amounts of multiple suspensions 31FL, 31FR, 31RL, and 31RR were corrected, but this is not limited to this. Front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xrIf the deviation of / dt can be suppressed, the control device may correct only the control amount of the front suspensions 31FL and 31FR among the multiple suspensions 31FL, 31FR, 31RL, and 31RR. In this case, the control device sets 1 to "r1" and "r2" and sets extremely large values ​​to "r3" to "r6" in the matrix R represented by the above determinant (D26), thereby correcting the damping force ΔF of the multiple front suspensions 31FL and 31FR. czij This can be derived.

[0078] Also, the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr If the deviation of / dt can be suppressed, the control device may correct only the control amount of the rear suspensions 31RL and 31RR among the multiple suspensions 31FL, 31FR, 31RL, and 31RR. In this case, the control device sets 1 to "r3" and "r4" and sets extremely large values ​​to "r1", "r2", "r5", and "r6" in the matrix R represented by the above determinant (D26), thereby correcting the damping force correction amount ΔF of the multiple rear suspensions 31RL and 31RR. czij This can be derived.

[0079] ·Front wheel steering angle δ f and rear wheel steering angle δ r By adjusting at least one of these, the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr / dt changes. Therefore, the control device 50 controls the front roll angular velocity dθ xf / dt and rear roll angular velocity dθ xr To suppress the deviation from / dt, the front wheel steering angle δ f and rear wheel steering angle δ r At least one of these may be corrected. Front wheel steering angle δ f When correcting this, the front wheel steering actuator that steers the front wheels FL and FR corresponds to the "actuator" mentioned above. Rear wheel steering angle δ rWhen correcting this, the rear wheel steering actuator that steers the rear wheels RL and RR corresponds to the "actuator" mentioned above.

[0080] For example, when correcting the operation of the rear wheel steering actuator, the control device can derive the correction amount for the control amount of the rear wheel steering actuator by setting "r6" to 1 and setting "r1" to "r5" to extremely large values ​​in the matrix R represented by the above determinant (D26). Similarly, when correcting the operation of the front wheel steering actuator, the control device can derive the correction amount for the control amount of the front wheel steering actuator by setting "r5" to 1 and setting "r1" to "r4" and "r6" to extremely large values ​​in the matrix R represented by the above determinant (D26).

[0081] In the above embodiment, the rotation angle around the roll center 41 on the front YZ plane Pyzf including the front axle 11F is defined as "front roll angle θ". xf The term "rear roll angle θ" is defined as the rotation angle around the roll center 41 in the rear YZ plane Pyzr including the rear axle 11R. xr It is defined as "front roll angle θ". However, it is not limited to this. For example, the rotation angle around the roll center 41 on the YZ plane including the front end of the vehicle body 12 is defined as "front roll angle θ". xf The rear roll angle θ is defined as the rotation angle around the roll center 41 on the YZ plane including the rear end of the vehicle body 12. xr It could also be defined as "."

[0082] The control device 50 is not limited to one that includes a CPU and ROM and performs software processing. In other words, the control device 50 may have any of the following configurations: (a), (b), and (c).

[0083] (a) The control device 50 comprises one or more processors that perform various processes according to a computer program. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to perform processes. The memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0084] (b) The control device 50 includes one or more dedicated hardware circuits that perform various processes. Examples of dedicated hardware circuits include application-specific integrated circuits, i.e., ASICs or FPGAs. ASIC is an abbreviation for "Application Specific Integrated Circuit," and FPGA is an abbreviation for "Field Programmable Gate Array."

[0085] (c) The control device 50 comprises one or more processors that execute a portion of the various processes according to a computer program, and one or more dedicated hardware circuits that execute the remaining processes of the various processes.

[0086] <Technical philosophy> The technical concepts that can be understood from the above embodiments and modified examples are described below. [Note 1] The actuator is A front wheel suspension is interposed between the vehicle body and the front wheel and is configured to allow the damper damping force to be changed. Includes a rear wheel suspension device interposed between the vehicle body and the rear wheel, and configured to allow adjustment of the damper damping force, Preferably, the derivation unit derives a control amount for adjusting at least one of the damper damping force of the front suspension and the damper damping force of the rear suspension as the control amount for the actuator.

[0087] [Note 2] The actuator includes a front wheel steering actuator that adjusts the front wheel steering angle, and a rear wheel steering actuator that adjusts the rear wheel steering angle, It is preferable that the deriving unit derives at least one of the control amount of the front wheel steering actuator and the control amount of the rear wheel steering actuator as the control amount of the actuator.

[0088] [Appendix 3] A vehicle control method for controlling the roll motion of the vehicle by operating an actuator capable of adjusting the roll motion of the vehicle, the method comprising: a process of acquiring front roll angle information including at least one of a roll angle and a roll angular velocity of the front portion of the vehicle body of the vehicle, and rear roll angle information including at least one of a roll angle and a roll angular velocity of the rear portion of the vehicle body of the vehicle, based on the torsional rigidity of a component of the vehicle located between the front wheels and the rear wheels of the vehicle, a process of deriving a control amount of the actuator based on the front roll angle information and the rear roll angle information, and a process of controlling the actuator based on the control amount.

[0089] Note that the expression "at least one" as used in the present specification means "one or more" of the desired options. As an example, the expression "at least one" as used in the present specification means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" as used in the present specification means "only one option" or "any combination of two or more options" if the number of options is three or more. [Description of Reference Signs]

[0090] 10...Vehicle 12...Vehicle body 12F...Front portion of vehicle body 12R...Rear portion of vehicle body 31FL, 31FR, 31RL, 31RR...Suspension (an example of actuator) 50... Control device (vehicle control device) 51…CPU (an example of a processing circuit) 100... Control Model M12…Acquisition part M13...Multiplication section (Constitutes an example of the derivation section) M30... Correction control amount derivation unit (Constitutes an example of a derivation unit) M50...Command control amount derivation unit (Constitutes an example of a derivation unit) FL, FR…Front wheel RL,RR…Rear wheel

Claims

1. A vehicle control device applicable to a vehicle equipped with an actuator capable of adjusting the vehicle's roll motion, which controls the roll motion of the vehicle by operating the actuator, An acquisition unit that acquires front roll angle information, including at least one of the roll angle and roll angular velocity of the front of the vehicle body, and rear roll angle information, including at least one of the roll angle and roll angular velocity of the rear of the vehicle body, based on the torsional rigidity of the vehicle components located between the front and rear wheels of the vehicle. The system includes a derivation unit that derives the control amount of the actuator based on the front roll angle information and the rear roll angle information. Vehicle control device.

2. The derivation unit derives a control amount that can suppress the discrepancy between the parameter indicated by the front roll angle information and the parameter indicated by the rear roll angle information. The vehicle control device according to claim 1.

3. The acquisition unit is, A model showing the relationship between steering angle information, which includes at least one of the steering angle of the front wheels and the steering angle of the rear wheels, the vehicle speed, the front roll angle information, and the rear roll angle information, comprising a roll motion model created considering the torsional rigidity of the components, Based on the roll motion model, the steering angle information and the front roll angle information and rear roll angle information corresponding to the vehicle speed are acquired. The vehicle control device according to claim 1 or claim 2.

4. The derivation unit uses a state feedback gain to derive a value corresponding to the front roll angle information and the rear roll angle information as the control amount. The vehicle control device according to claim 3.

5. A vehicle control program that controls the roll motion of a vehicle by activating an actuator that adjusts the roll motion of the vehicle, In the processing circuit, A process to obtain front roll angle information, including at least one of the roll angle and roll angular velocity of the front of the vehicle body, and rear roll angle information, including at least one of the roll angle and roll angular velocity of the rear of the vehicle body, based on the torsional rigidity of the vehicle components located between the front and rear wheels of the vehicle. A process to derive the control amount of the actuator based on the front roll angle information and the rear roll angle information, The process of controlling the actuator based on the control amount is executed. Vehicle control program.

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