Vehicle control system

Abstract

When performing vibration damping control based on parameters related to the vertical movement of each wheel of a vehicle, the roll component, heap component, and pitch component are appropriately reflected in this vibration damping control. [Solution] Based on the result of comparing the heap component, pitch component, and roll component included in the parameters related to the vertical movement of each wheel of the vehicle with an upper limit specified value, a high-pass filter is set to cut out components of these parameters below a predetermined frequency and filtering is performed. The high-pass filter includes a first high-pass filter. The first high-pass filter is set when at least one of the heap component, pitch component, and roll component is greater than or equal to an upper limit specified value. The first high-pass filter includes a first heap filter, a first pitch filter weaker than the first heap filter, and a first roll filter weaker than the first pitch filter.

Description

Technical Field

[0001] The present disclosure relates to a technique for performing vibration damping control of a vehicle.

Background Art

[0002] Patent Document 1 discloses vibration damping control using a road surface displacement map that represents the correspondence relationship between road surface displacement (road surface unevenness) and position. In this vibration damping control, the road surface displacement at a predetermined position ahead of the vehicle is recognized from the road surface displacement map. The control amount of the active suspension is calculated in advance according to the recognized road surface displacement. Then, the active suspension is controlled at the timing when the wheels pass the predetermined position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0004] In the present disclosure, vibration damping control based on parameters related to the vertical motion of each wheel of a vehicle is considered. The parameters related to the vertical motion of each wheel can be calculated, for example, based on detection values of sensors that detect the vertical behavior of each wheel. However, the vertical motion related parameters include extremely low frequency components derived from elevation changes and the like. Therefore, in vibration damping control, it is desirable to perform filtering using a high-pass filter to cut the extremely low frequency components from the vertical motion related parameters. However, if a high-pass filter that is stronger than necessary is used, the roll component derived from the different vertical displacements of the left and right wheels will also be cut from the vertical motion related parameters.

[0005] When vibration damping control is performed based on vertical motion-related parameters with the roll component cut out, the roll component is not reflected in the vibration damping control, resulting in a reduced control effect. This problem can be solved by using a weak high-pass filter for filtering. However, in this case, the heap and pitch components, which originate from the same vertical displacement of the left and right wheels that are susceptible to changes in elevation, will remain. In that case, an excessive amount of control to try to cancel out the heap and pitch components may reduce the control effect.

[0006] One objective of this disclosure is to provide a technology that can appropriately reflect roll, heap, and pitch components in vibration damping control based on parameters related to the vertical movement of each wheel of a vehicle. [Means for solving the problem]

[0007] This disclosure relates to a control system applied to a vehicle and has the following features: The system comprises sensors that detect the behavior of each wheel of the vehicle, actuators that control the suspension stroke of each wheel, and one or more processing circuits that perform vibration damping control of the vehicle by controlling the actuators based on the values ​​detected by the sensors. The vibration damping control includes calculating parameters related to the vertical movement of each wheel based on sensor detection values, setting a high-pass filter to cut components below a predetermined frequency from the parameters based on the result of comparing the parameters with upper limit specified values, and calculating each control amount of the actuator that controls the suspension stroke based on the parameters from which components below a predetermined frequency have been cut by filtering using the high-pass filter. The parameters include a heap component in which all four wheels of the vehicle move up and down in the same way, a pitch component in which the left and right wheels of the vehicle move up and down in the same way, and the front and rear wheels of the vehicle move up and down differently, and a roll component in which the left and right wheels of the vehicle move up and down differently. The high-pass filter includes a first high-pass filter which is set when at least one of the heap component, pitch component, and roll component is greater than or equal to an upper limit specified value. The first high-pass filter includes a first heap filter, a first pitch filter which is weaker than the first heap filter, and a first roll filter which is weaker than the first pitch filter. When a first high-pass filter is set in the high-pass filter settings, the filtering process will be as follows: the heap component will be filtered by either the first heap filter or the first pitch filter; the roll component will be filtered by either the first pitch filter or the first roll filter, whichever is different from the filter applied to the heap component; and the pitch component will be filtered by either the first heap filter, the first pitch filter, or the first roll filter, whichever is the same as the filter applied to the heap component or the roll component, or by a filter different from the filters applied to both the heap and roll components. [Effects of the Invention]

[0008] According to this disclosure, filtering is performed by setting a high-pass filter that cuts out components of the parameter below a predetermined frequency based on the result of comparing the heap component, pitch component, and roll component included in the parameter related to the vertical motion of each wheel of the vehicle with an upper limit specified value. The high-pass filter includes a first high-pass filter. The first high-pass filter is set when at least one of the heap component, pitch component, and roll component is greater than or equal to an upper limit specified value. The first high-pass filter includes a first heap filter, a first pitch filter weaker than the first heap filter, and a first roll filter weaker than the first pitch filter.

[0009] If a first high-pass filter is set as the high-pass filter for filtering, the first heap filter or the first pitch filter will be applied to filter the heap component. For filtering the roll component, a filter different from the one applied to the heap component will be applied from among the first pitch filter and the first roll filter. For filtering the pitch component, a filter that is the same as the one applied to the heap component or the roll component, or a filter different from the filters applied to the heap component and the roll component, will be applied from among the first heap filter, the first pitch filter, and the first roll filter.

[0010] When at least one of the heap, pitch, and roll components exceeds a specified upper limit, filtering by applying the three types of filters described above (heap, pitch, and roll) to these components makes it possible to cut out extremely low-frequency components from the heap component while retaining the roll component. Therefore, it becomes possible to appropriately reflect the roll, heap, and pitch components in the vibration damping control performed based on the filtered parameters, thereby enhancing the control effect on each of the upper limit motion modes of heap, pitch, and roll. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing an example of the vehicle configuration according to the embodiment. [Figure 2] This is a conceptual diagram showing an example of the suspension configuration according to the embodiment. [Figure 3] This flowchart shows an example of vibration control processing according to the embodiment. [Modes for carrying out the invention]

[0012] Embodiments of this disclosure will be described with reference to the attached drawings.

[0013] 1. Vehicle control system Figure 1 is a schematic diagram showing an example of the configuration of a vehicle 1 equipped with a vehicle control system 10 according to an embodiment. The vehicle 1 is equipped with wheels 2 and suspension 3. The wheels 2 include a left front wheel 2FL, a right front wheel 2FR, a left rear wheel 2RL, and a right rear wheel 2RR. The left front wheel 2FL and the right front wheel 2FR form the left and right wheels on the front axle side, and the left rear wheel 2RL and the right rear wheel 2RR form the left and right wheels on the rear axle side. Suspensions 3FL, 3FR, 3RL, and 3RR are provided for each of the left front wheel 2FL, right front wheel 2FR, left rear wheel 2RL, and right rear wheel 2RR, respectively. In the following description, unless otherwise specified, each wheel will be referred to as wheel 2, and each suspension will be referred to as suspension 3.

[0014] Figure 2 is a conceptual diagram showing an example configuration of the suspension 3. The suspension 3 is provided to connect the unsprung structure 4 and the sprung structure 5 of the vehicle 1. The unsprung structure 4 includes the wheels 2. The suspension 3 includes a spring 3S, a damper (shock absorber) 3D, and an actuator 3A. The spring 3S, damper 3D, and actuator 3A are provided in parallel between the unsprung structure 4 and the sprung structure 5. The spring constant of the spring 3S is K. The damping coefficient of the damper 3D is C. The damping force of the damper 3D may be variable. The actuator 3A applies a vertical control force Fc between the unsprung structure 4 and the sprung structure 5.

[0015] Here, we define the terms. "Road surface displacement Zr" is the vertical displacement of the road surface RS. "Unsprung displacement Zu" is the vertical displacement of the unsprung structure 4. "Sprung displacement Zs" is the vertical displacement of the sprung structure 5. "Unsprung velocity Zu'" is the vertical velocity of the unsprung structure 4. "Sprung velocity Zs'" is the vertical velocity of the sprung structure 5. "Unsprung acceleration Zu''" is the vertical acceleration of the unsprung structure 4. "Sprung acceleration Zs''" is the vertical acceleration of the sprung structure 5. Note that the sign of each parameter is positive when it is upward and negative when it is downward.

[0016] Wheel 2 moves on road surface RS. In the following description, parameters related to the vertical motion of wheel 2 are referred to as "vertical motion parameters". Examples of the vertical motion parameters include the aforementioned road surface displacement Zr, unsprung displacement Zu, unsprung velocity Zu', unsprung acceleration Zu'', sprung displacement Zs, sprung velocity Zs', sprung acceleration Zs'', and the like. The vertical motion parameters can also be said to be "road surface displacement parameters" related to the road surface displacement Zr.

[0017] The vehicle control system 10 according to the embodiment includes a sensor 20. The sensor 20 includes a vehicle speed sensor (wheel speed sensor) 21 that detects a vehicle speed V of the vehicle 1, a sprung acceleration sensor 22 that detects the sprung acceleration Zs'', and the like. The sprung acceleration sensor 22 is provided for each of the left front wheel 2FL, the right front wheel 2FR, the left rear wheel 2RL, and the right rear wheel 2RR. The sensor 20 may include a stroke sensor that detects a stroke ST (=Zs-Zu) which is a relative displacement between the sprung structure 5 and the unsprung structure 4. The sensor 20 may include an unsprung acceleration sensor. In addition, the sensors may include a lateral acceleration sensor, a yaw rate sensor, a steering angle sensor, and the like.

[0018] The vehicle control system 10 further includes one or a plurality of processing circuits 30 (hereinafter simply referred to as "processing circuit 30") and one or a plurality of storage devices 40 (hereinafter simply referred to as "storage device 40"). The processing circuit 30 executes various processes. For example, the processing circuit 30 includes a CPU (Central Processing Unit). The storage device 40 stores various types of information. Examples of the storage device 40 include a volatile memory, a non-volatile memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), and the like. The functions of the vehicle control system 10 may be implemented by the processing circuit 30 executing a vehicle control program. The vehicle control program may be recorded on a computer-readable recording medium.

[0019] The vehicle control system 10 (processing circuit 30) controls the suspension 3. Typically, the vehicle control system 10 (processing circuit 30) performs vibration suppression control that controls the suspension 3 to suppress vibration of the sprung structure 5 of the vehicle 1 (target vehicle). For example, the vehicle control system 10 (processing circuit 30) controls the actuator 3A to generate a vertical control force Fc between the unsprung structure 4 and the sprung structure 5, thereby suppressing the vibration of the sprung structure 5. Hereinafter, such vibration suppression control will be described in further detail.

[0020] 2. Vibration Suppression Control

[0021] As an example, in the following description, a case where the road surface displacement related value is the unsprung displacement Zu or the sprung displacement Zs is considered. For generalization, "unsprung displacement" or "sprung displacement" in the following description shall be read as "road surface displacement related value".

[0022] The unsprung displacement Zu and the sprung displacement Zs can be calculated based on the detection value of the sensor 20. However, since the detection value of the sensor 20 includes an extremely low frequency component derived from altitude change or the like, the unsprung displacement Zu or the sprung displacement Zs calculated based on the detection value also includes such an extremely low frequency component. Therefore, in the vibration suppression control, it is desirable to perform filtering using a high-pass filter to cut the extremely low frequency component. However, if an excessively strong high-pass filter is used, the left-right wheel opposite phase component (that is, the roll component) derived from different vertical displacements of the left and right wheels will also be cut from the unsprung displacement Zu or the sprung displacement Zs.

[0023] When vibration damping control is performed based on unsprung displacement Zu or sprung displacement Zs with the roll component cut out, the roll component is not reflected in the vibration damping control, resulting in a reduced control effect. This problem can be solved by using a weak high-pass filter for filtering. However, in this case, the in-phase components of the left and right wheels (four-wheel in-phase components and left and right wheels in-phase and front and rear wheels out-of-phase components; i.e., heap components and pitch components), which originate from the same vertical displacement of the left and right wheels that are susceptible to changes in altitude, remain. In that case, an excessive amount of control to try to cancel out the heap and pitch components may reduce the control effect.

[0024] Therefore, in this embodiment, in order to appropriately reflect the roll component, heap component, and pitch component in the vibration damping control, a high-pass filter used for filtering is set by referring to the state variables (specifically, acceleration, velocity, or displacement) of the sprung mass or unsprung mass. Figure 3 is a flowchart of an example of the vibration damping control process according to this embodiment. The processing routine shown in Figure 3 is repeatedly executed, for example, by the processing circuit 30.

[0025] In the example shown in Figure 3, in step S11, the detected value (sensor value) of the sensor 20 is acquired. The sensor value includes the vehicle speed acquired by the vehicle speed sensor 21 and the sprung acceleration Zs'' acquired by the sprung acceleration sensor 22. When calculating the unsprung displacement Zu, the sensor value may also include the stroke ST acquired by the stroke sensor and the unsprung acceleration acquired by the unsprung acceleration sensor. The stroke ST may be estimated based on the sprung acceleration Zs'' by an observer configured based on a single-wheel two-degree-of-freedom model.

[0026] Following step S11, in step S12, the acceleration components of the sprung mass (heap component Zg'', roll component Φg'', and pitch component Θg'') are calculated. Each acceleration component is calculated by the following equations (1) to (3), where the positions of the three sprung mass acceleration sensors 22, provided on the left front wheel 2FL, the right front wheel 2FR, and the right rear wheel 2RR, and the values ​​of these sensors acquired in step S11 (i.e., sprung mass acceleration Zs'' (s=1~3)) are used as variables.

[0027]

number

[0028] In equations (1) to (3), L1, L2, L3, and Lg are the x-direction positions of the sprung mass acceleration sensor 22 of the right front wheel 2FR, the x-direction positions of the sprung mass acceleration sensor 22 of the left front wheel 2FL, the x-direction positions of the sprung mass acceleration sensor 22 of the right rear wheel 2RR, and the x-direction positions of the sprung mass center of gravity, respectively. Also, W1, W2, and W3 are the y-direction positions of the sprung mass acceleration sensor 22 of the right front wheel 2FR, the y-direction positions of the sprung mass acceleration sensor 22 of the left front wheel 2FL, and the y-direction positions of the sprung mass acceleration sensor 22 of the right rear wheel 2RR, respectively. Furthermore, equations (1) to (3) assume a coordinate system where the vehicle direction of travel is x, the left-right direction is y, and the up-down direction is z.

[0029] Furthermore, each velocity component of the sprung mass (heap component Zg', roll component Φg', and pitch component Θg') is calculated by the first integral of each acceleration component of the heap component Zg'', roll component Φg'', and pitch component Θg'', while each displacement component of the sprung mass (heap component Zg, roll component Φg, and pitch component Θg) is calculated by the second integral of each acceleration component of the heap component Zg'', roll component Φg'', and pitch component Θg''.

[0030] In step S12, the displacement components of the unsprung mass (heap component Zg, roll component Φg, and pitch component Θg) may be calculated. Each displacement component is calculated, for example, by decomposing the difference (Zu=ST-Zs) between the stroke ST obtained in step S11 and the integral values ​​obtained by integrating the sprung acceleration Zs'' (s=1~4) obtained in step S11 twice into each vertical motion mode according to the following equations (4)~(7).

[0031]

number

[0032] In equations (4) to (7), Zufin represents the heap component of the front left and right wheels, Zufin represents the roll component of the front left and right wheels, Zurin represents the heap component of the rear left and right wheels, and Zurin represents the roll component of the rear left and right wheels. Also, Z1 represents the unsprung displacement Zu of the right front wheel 2FR, Z2 represents the unsprung displacement Zu of the left front wheel 2FL, Z3 represents the unsprung displacement Zu of the right rear wheel 2RR, and Z4 represents the unsprung displacement Zu of the left rear wheel 2RL.

[0033] The heap component Zg of the unsprung mass is calculated, for example, as the sum of the heap component Zufin and the heap component Zurin. The roll component Φg of the unsprung mass is calculated, for example, as the sum of the roll component Zufan and the roll component Zuran. The pitch component Θg of the unsprung mass is calculated, for example, as the sum of the heap component Zufin and the roll component Zuran, or the sum of the heap component Zurin and the roll component Zufan. The heap components Zufin and Zurin of the left and right wheels may be decomposed into in-phase components for the front and rear wheels (the sum of the heap components Zufin and Zurin divided by 2) and out-of-phase components for the front and rear wheels (the difference between the heap components Zufin and Zurin divided by 2).

[0034] As another example, the unsprung acceleration Zu'' detected by the unsprung acceleration sensor may be used to calculate the displacement components of the unsprung center of gravity (heap component Zg, roll component Φg, and pitch component Θg) using a method similar to the method for calculating each acceleration component of the sprung center of gravity using equations (1)-(3).

[0035] Following step S12, step S13 determines whether the state variable (acceleration, velocity, or displacement) of the sprung mass calculated in step S12 is greater than or equal to a predetermined upper limit. If the state variable of the unsprung mass was calculated in step S12, instead of determining the state variable of the sprung mass, it may be determined whether the state variable of the unsprung mass is greater than or equal to a predetermined upper limit.

[0036] The state variable for the sprung mass (or unsprung mass) may be the value calculated in step S12, or it may be the moving average of multiple state variables obtained by going back a predetermined sampling period from the current processing routine. The upper limit default value is set in advance for state variables (acceleration, velocity, or displacement) that exceed the actuator's capacity or suspension stroke, or state variables that are close to such an upper limit, and the corresponding value (acceleration, velocity, or displacement) to be compared with them.

[0037] The determination in step S13 is made by focusing on one of the acceleration component, velocity component, or displacement component. Specifically, when a comparison is made based on the acceleration component, it is determined whether at least one of the heap component Zg'', roll component Φg'', and pitch component Θg'' is greater than or equal to the upper limit default value for the acceleration component. When a comparison is made based on the velocity component, it is determined whether at least one of the heap component Zg', roll component Φg', and pitch component Θg' is greater than or equal to the upper limit default value for the velocity component. When a comparison is made based on the displacement component, it is determined whether at least one of the heap component Zg, roll component Φg, and pitch component Θg is greater than or equal to the upper limit default value for the displacement component.

[0038] If the result of step S13 is positive, the process in step S14 is performed. In step S14, filtering is performed using a first high-pass filter. Here, the first high-pass filter includes three types of high-pass filters. Specifically, the three types of high-pass filters are a first heap filter, a first pitch filter weaker than the first heap filter, and a first roll filter weaker than the first pitch filter. Here, a "weak" high-pass filter means that it has a low cutoff frequency (low frequency side), a small filter order, or a small number of filter stages.

[0039] For example, the cutoff frequency of the first heap filter is set to a frequency that cuts out extremely low-frequency components (e.g., components below 0.5 Hz) that originate from altitude changes, and the cutoff frequency of the first roll filter is set to a frequency that leaves in the frequency components that include the roll component (e.g., 0.2 Hz). The cutoff frequency of the first pitch filter is set to a frequency midway between these frequencies (e.g., 0.3 to 0.4 Hz).

[0040] The first heap filter is applied to the heap component (acceleration, velocity, or displacement component), the first pitch filter is applied to the pitch component (acceleration, velocity, or displacement component), and the first roll filter is applied to the roll component (acceleration, velocity, or displacement component). However, any two of the filters may be the same. For example, the same filter (first heap filter or first pitch filter) may be applied to the heap component and the pitch component, and the first roll filter may be applied to the roll component. Alternatively, the first heap filter may be applied to the heap component, and the same filter (first pitch filter or first roll filter) may be applied to the pitch component and the roll component.

[0041] Furthermore, the first high-pass filters applied to the acceleration, velocity, and displacement components may be made strongest for the displacement component and weakest for the velocity and acceleration components in that order. Specifically, the first heap filters applied to the heap component Zg, heap component Zg', and heap component Zg'' may be weakest in that order, the first pitch filters applied to the pitch component Θg, pitch component Θg', and pitch component Θg'' may be weakest in that order, and the first roll filters applied to the roll component Φg, roll component Φg', and roll component Φg'' may be weakest in that order.

[0042] If the result of step S13 is negative, the process in step S15 is performed. In step S15, filtering is performed using a second high-pass filter. The second high-pass filter, like the first high-pass filter, contains three types of filters. Specifically, the three types of high-pass filters are a second heap filter, a second pitch filter which is weaker than the second heap filter, and a second roll filter which is weaker than the second pitch filter. Here, the second heap filter is a weaker filter than the first heap filter. Also, the second pitch filter is a weaker filter than the first pitch filter, and the second roll filter is a weaker filter than the first roll filter.

[0043] A negative result in step S13 means that the state quantity of the sprung mass or unsprung mass calculated in step S12 is less than the upper limit default value. Therefore, weaker filters are used for the second heap filter, second pitch filter, and second roll filter than for the first heap filter, first pitch filter, and first roll filter, respectively. Furthermore, the fact that the state quantity of the sprung mass or unsprung mass is less than the upper limit default value means that the effect of using the single high-pass filter described above is small. Therefore, in step S15, filtering may be performed using any one of the second heap filter, second pitch filter, and second roll filter.

[0044] Furthermore, as with the first high-pass filter, any two of the filters applied to the heap component, pitch component, and roll component may be the same. That is, the same filter (second heap filter or second pitch filter) may be applied to the heap component and pitch component, and the second roll filter may be applied to the roll component. Alternatively, the second heap filter may be applied to the heap component, and the same filter (second pitch filter or second roll filter) may be applied to the pitch component and roll component.

[0045] Furthermore, similar to the first high-pass filter, the second high-pass filters applied to the acceleration, velocity, and displacement components may be made strongest for the displacement component and weakest for the velocity and acceleration components in that order. That is, the second heap filters applied to the heap component Zg, heap component Zg', and heap component Zg'' may be weakest in that order, the second pitch filters applied to the pitch component Θg, pitch component Θg', and pitch component Θg'' may be weakest in that order, and the second roll filters applied to the roll component Φg, roll component Φg', and roll component Φg'' may be weakest in that order.

[0046] Following step S14 or S15, in step S16, the target control force Fc of the actuator 3A is calculated based on the state variables of the filtered sprung mass. The target control force Fc is, for example, the target control force of the sprung velocity feedback control that suppresses vibration based on each velocity component of the filtered sprung mass. The target control force Fc (c=1~4) based on each velocity component of the filtered sprung mass is calculated, for example, using the following equation (8).

[0047]

number

[0048] In equation (8), F1 is the target control force Fc of actuator 3A of the right front wheel 2FR, F2 is the target control force Fc of actuator 3A of the left front wheel 2FL, F3 is the target control force Fc of actuator 3A of the right rear wheel 2RR, and F4 is the target control force Fc of actuator 3A of the left rear wheel 2RL. lf is the distance from the center of gravity of the sprung mass to the front wheels (front overhang), lr is the distance from the center of gravity of the sprung mass to the rear wheels (rear overhang). Tf is the tread of the front left and right wheels, and Tr is the tread of the rear left and right wheels. *Zg' is the vertical velocity after filtering, *Φg' is the roll angular velocity, and *Θg' is the pitch angular velocity after filtering. αzg, αΦ, and αΘ are the gains corresponding to each velocity term.

[0049] In another example, the target control force Fc is the target control force of a sprung velocity feedback control that suppresses vibration based on each displacement component of the filtered sprung mass. In yet another example, the target control force Fc is the target control force of a sprung velocity feedback control that suppresses vibration based on each acceleration component of the filtered sprung mass. In yet another example, the target control force Fc is the target control force of a sprung velocity feedback control that suppresses vibration by summing up two or more components from each velocity component, each displacement component, and each angular velocity component of the filtered sprung mass.

[0050] In step S16, if the state quantity of the unsprung center of gravity has been calculated in step S12, the target control force Fc of actuator 3A may be calculated based on the filtered unsprung center of gravity state quantity instead of the filtered sprung center of gravity state quantity. In this case, the target control force Fc is the target control force of the sprung velocity feedback control that suppresses vibration based on each displacement component of the filtered unsprung center of gravity. The target control force Fc (c=1~4) based on each displacement component of the filtered unsprung center of gravity is calculated, for example, using the following equations (9)~(12).

[0051]

number

[0052] In equations (9) to (12), F1 is the target control force Fc of actuator 3A of the right front wheel 2FR, F2 is the target control force Fc of actuator 3A of the left front wheel 2FL, F3 is the target control force Fc of actuator 3A of the right rear wheel 2RR, and F4 is the target control force Fc of actuator 3A of the left rear wheel 2RL. *Zufin is the heap component of the front left and right wheels after filtering, *Zufin is the roll component of the front left and right wheels after filtering, *Zurin is the heap component of the rear left and right wheels after filtering, and *Zurin is the roll component of the rear left and right wheels after filtering. αfin is the in-phase gain of the front left and right wheels, αfan is the out-of-phase gain of the front left and right wheels, αrin is the in-phase gain of the rear left and right wheels, and αran is the out-of-phase gain of the rear left and right wheels.

[0053] Following step S16, in step S17, the actuator 3A is controlled to generate the target control force Fc calculated in step S16.

[0054] 3. Effects According to the embodiments described above, filtering is performed by applying three types of filters—heap, pitch, and roll—to the heap component, pitch component, and roll component. This makes it possible to cut out extremely low-frequency components from the heap component while retaining the roll component. In particular, when at least one of the heap component, pitch component, and roll component is above the upper limit specified value, filtering is performed using the first heap filter, the first pitch filter, and the first roll filter. This makes it possible to cut out extremely low-frequency components from the heap component while retaining the roll component when the effect of using the single high-pass filter described above would be significant. Consequently, it is possible to appropriately reflect the roll component, heap component, and pitch component in the vibration damping control performed based on the filtered parameters, thereby enhancing the control effect on each upper limit motion mode of the heap, pitch, and roll. [Explanation of Symbols]

[0055] 1…Vehicle 2...wheels 3…Suspension 3A… Actuator 10…Vehicle control system 20...Sensor

Claims

1. A control system applied to a vehicle, A sensor for detecting the behavior of each wheel of the vehicle, Actuators that control the suspension stroke of each of the aforementioned wheels, The system includes one or more processing circuits that perform vibration control of the vehicle by controlling the actuator based on the detected value of the sensor, The vibration damping control, Based on the values ​​detected by the aforementioned sensors, the parameters related to the vertical movement of each wheel are calculated, Based on the results of comparing the aforementioned parameters with the upper limit specified value, a high-pass filter is set to cut out components below a predetermined frequency from the aforementioned parameters. This includes calculating each control amount of the actuator that controls the suspension stroke based on the parameters from which components below a predetermined frequency have been cut off by filtering using the high-pass filter, The parameters include a heap component in which all four wheels of the vehicle move up and down in the same way, a pitch component in which the left and right wheels of the vehicle move up and down in the same way and the front and rear wheels of the vehicle move up and down in different ways, and a roll component in which the left and right wheels of the vehicle move up and down in different ways. The high-pass filter includes a first high-pass filter that is set when at least one of the heap component, the pitch component, and the roll component is greater than or equal to the upper limit specified value. The first high-pass filter includes a first heap filter, a first pitch filter weaker than the first heap filter, and a first roll filter weaker than the first pitch filter. In the setting of the high-pass filter, if the first high-pass filter is set, in the filtering, the first heap filter or the first pitch filter is applied to the heap component, the first pitch filter and the first roll filter which are different from the filter applied to the heap component are applied to the roll component, and the same filter as the filter applied to the heap component or the roll component from the first heap filter, the first pitch filter and the first roll filter is applied to the pitch component, or a filter which are different from the filters applied to the heap component and the roll component is applied. A vehicle control system characterized by the following features.

2. A control system according to claim 1, In the setting of the high-pass filter described above, if the first high-pass filter is set, then in the filtering, the first heap filter is applied to the heap component, the first roll filter is applied to the roll component, and the first pitch filter is applied to the pitch component. A vehicle control system characterized by the following features.

3. A control system according to claim 1 or 2, The high-pass filter includes a second high-pass filter which is set when all of the heap component, pitch component, and roll component are less than the upper limit specified value. The second high-pass filter includes a second heap filter weaker than the first heap filter, a second pitch filter weaker than the first pitch filter, and a second roll filter weaker than the first roll filter. If the second high-pass filter is set in the setting of the high-pass filter, then in the filtering, any of the second heap filter, second pitch filter, and second pitch filter is applied to the heap component, pitch component, and roll component. A vehicle control system characterized by the following features.

4. A control system according to claim 1 or 2, The high-pass filter includes a second high-pass filter which is set when all of the heap component, pitch component, and roll component are less than the upper limit specified value. The second high-pass filter includes a second heap filter, a second pitch filter weaker than the second heap filter, and a second roll filter weaker than the second pitch filter. If the second high-pass filter is set in the setting of the high-pass filter, then in the filtering, the second heap filter or the second pitch filter is applied to the heap component, the second pitch filter and the second roll filter which are different from the filter applied to the heap component are applied to the roll component, and the same filter as the filter applied to the heap component or the roll component from among the second heap filter, the second pitch filter and the second roll filter is applied to the pitch component, or a filter which are different from the filters applied to the heap component and the roll component is applied. A vehicle control system characterized by the following features.

5. A control system according to claim 4, If the second high-pass filter is set in the setting of the high-pass filter, then in the filtering, the second heap filter is applied to the heap component, the second roll filter is applied to the roll component, and the second pitch filter is applied to the pitch component. A vehicle control system characterized by the following features.

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