Suspension controls and suspension

Abstract

A technology for improving the sense of alignment with the vehicle felt by the driver can be realized. A suspension control device for controlling the damping force of a vehicle suspension includes a target control amount calculation unit (89) that sets a target control amount, which is referenced when controlling the damping force of the suspension, so that the phase cycle of the roll angle of the vehicle and the phase cycle of the pitch angle are close to a synchronous state, so that the magnitude of the extension side damping force is greater than the magnitude of the contraction side damping force on the front wheel side of the vehicle, and so that the contraction side damping force is greater than or equal to the extension side damping force on the rear wheel side of the vehicle.

Description

Technical Field

[0001] The present invention relates to a suspension control device and a suspension device. Background Art

[0002] In controlling the running state of a vehicle, from the perspective of enhancing the safety of vehicle running, there is disclosed a method of synchronizing roll and pitch as vehicle motions by using a technique of controlling brakes or suspension (for example, see Patent Document 1).

[0003] Patent Document 1: US2004 / 0024504A

[0004] However, the above patent document does not disclose a specific control method for synchronizing roll and pitch.

[0005] One aspect of the present invention is to achieve a suspension control that is capable of synchronizing the roll and pitch of a vehicle. Summary of the Invention

[0006] In order to solve the above problems, a suspension control device according to one aspect of the present invention controls the damping force of the suspension of a vehicle. The suspension control device includes a target control amount calculation unit, which sets a target control amount to be referred to when controlling the damping force of the suspension, so that the phase period of the roll angle of the vehicle is close to the phase period of the pitch angle of the vehicle. In addition, on the front wheel side of the vehicle, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side, and on the rear wheel side of the vehicle, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side.

[0007] In order to solve the above problems, a suspension device according to another aspect of the present invention includes a suspension of a vehicle and a control unit for controlling the damping force of the suspension, wherein the control unit includes a target control amount calculation unit, which sets a target control amount to be referred to when controlling the damping force of the suspension, so that the phase period of the roll angle of the vehicle is close to the phase period of the pitch angle of the vehicle. On the front wheel side of the vehicle, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side, and on the rear wheel side of the vehicle, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side.

[0008] According to aspects of the present invention, the pitch angle of the vehicle body can be easily designed, and the responsiveness of control can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a diagram schematically showing an example of the configuration of a vehicle according to the first embodiment of the present invention.

[0010] Figure 2is a block diagram showing an example of a functional configuration of a suspension control portion according to the first embodiment of the present invention.

[0011] Figure 3 is a block diagram showing an example of a functional configuration of a roll attitude control portion according to the first embodiment of the present invention.

[0012] Figure 4 : is a block diagram showing an example of a functional configuration of a roll posture target control amount calculation section according to the first embodiment of the present invention.

[0013] Figure 5 : is a block diagram showing an example of a functional configuration of a target pitch angle calculation section according to the first embodiment of the present invention.

[0014] Figure 6 1 is a block diagram showing an example of a functional configuration of a target control amount operation section according to the first embodiment of the present invention.

[0015] Figure 7 is a schematic diagram showing a mechanism for generating a pitching moment according to a first embodiment of the present invention.

[0016] Figure 8 is a graph showing an example of the relationship between the damping force and the suspension stroke speed of the front and rear wheels according to the first embodiment of the present invention.

[0017] Figure 9 1 is a schematic diagram showing the resultant of the damping forces of the left and right wheels on the rear wheel side according to the first embodiment of the present invention.

[0018] Figure 10 1 is a flowchart showing the flow of damping force control according to the first embodiment of the present invention.

[0019] Figure 11 is a graph showing the definition of the rear wheel side target differential damping gradient according to the first embodiment of the present invention.

[0020] Figure 12 : is a block diagram showing an example of a functional configuration of a target pitch angle calculation section according to the second embodiment of the present invention.

[0021] Figure 13 : is a block diagram showing an example of a functional configuration of a target pitch angle calculation section according to a third embodiment of the present invention.

[0022] Reference Mark List

[0023] 89: Roll attitude target control amount calculation unit (target control amount calculation unit)

[0024] 92, 95: Gain multiplication unit

[0025] 96: Gain setting unit

[0026] 891: Target pitch angle calculation unit

[0027] 893: Target differential damping gradient calculation unit

[0028] 894: Target Control Quantity Calculation Unit

[0029] 900: Vehicle

[0030] 905: Rear wheel side telescopic determination unit

[0031] 908: Rear wheel target control amount calculation unit

[0032] 921: Target damping gradient calculation unit for front wheel retraction side DETAILED DESCRIPTION

[0033] [First embodiment]

[0034] Hereinafter, a first embodiment of the present invention will be described in detail.

[0035] [Vehicle Configuration]

[0036] Figure 1 is a diagram schematically showing an example of the configuration of a vehicle 900 according to the present embodiment. Figure 1 As shown, vehicle 900 includes a suspension device (suspension) 100, a vehicle body 200, wheels 300, tires 310, a steering member 410, a steering shaft 420, a torque sensor 430, a steering angle sensor 440, a torque applying portion 460, a rack and pinion mechanism 470, a rack shaft 480, an engine 500, an electronic control unit (ECU) (control device, control portion) 600, a power generation device 700, and a battery 800. Here, suspension device 100 and ECU 600 constitute the suspension device according to this embodiment.

[0037] A wheel 300 mounted with a tire 310 is suspended from the vehicle body 200 by a suspension device 100. Since the vehicle 900 is a four-wheeled vehicle, the suspension device 100, the wheel 300, and the tire 310 are provided on each of the four wheels.

[0038] The tires and wheels of the left front wheel, right front wheel, left rear wheel, and right rear wheel are also referred to as tire 310A and wheel 300A, tire 310B and wheel 300B, tire 310C and wheel 300C, and tire 310D and wheel 300D, respectively. Hereinafter, similarly, the configurations attached to the left front wheel, right front wheel, left rear wheel, and right rear wheel may be indicated by adding reference letters "A," "B," "C," and "D."

[0039] The suspension device 100 includes a hydraulic shock absorber (shock absorber), an upper arm, and a lower arm. Furthermore, as an example, the hydraulic shock absorber includes a solenoid valve, which is an electromagnetic valve for adjusting the damping force generated by the hydraulic shock absorber. However, this embodiment is not limited to this, and the hydraulic shock absorber may use an electromagnetic valve other than a solenoid valve as the electromagnetic valve for adjusting the damping force. For example, the hydraulic shock absorber may be configured such that a solenoid valve using electromagnetic fluid (magnetic fluid) is provided as the aforementioned solenoid valve.

[0040] The power generation device 700 is attached to the engine 500 , and the electricity generated by the power generation device 700 is stored in the battery 800 .

[0041] The steering member 410 operated by the driver is connected to one end of the steering shaft 420 so as to be able to transmit torque, and the other end of the steering shaft 420 is connected to the rack and pinion mechanism 470 .

[0042] The rack and pinion mechanism 470 converts the rotation of the steering shaft 420 about the axis into the displacement in the axial direction of the rack shaft 480. When the rack shaft 480 is displaced in the axial direction, the wheels 300A and 300B are steered via the tie rods and the knuckle arms.

[0043] Torque sensor 430 detects the steering torque applied to steering shaft 420, in other words, the steering torque applied to steering member 410, and provides a torque sensor signal indicating the detection result to ECU 600. More specifically, torque sensor 430 detects the torsion of a torsion bar built into steering shaft 420 and outputs the detection result as a torque sensor signal. As torque sensor 430, a well-known sensor such as a Hall effect IC, an MR element, or a magnetostrictive torque sensor can be used.

[0044] The steering angle sensor 440 detects the steering angle of the steering member 410 and provides the detection result to the ECU 600 .

[0045] The torque applying unit 460 applies assist torque or reaction torque to the steering shaft 420 according to the steering control amount supplied from the ECU 600. The torque applying unit 460 includes a motor that generates assist torque or reaction torque according to the steering control amount, and a torque transmitting mechanism that transmits the torque generated by the motor to the steering shaft 420.

[0046] In the above description, "connected so as to be able to transmit torque" means that the components are connected in such a manner that the rotation of one component causes the rotation of the other component. For example, this includes at least cases where one component and another component are integrally molded, where one component is directly or indirectly fixed to another component, and where one component and another component are connected so as to interlock with each other via a joint component or the like.

[0047] Furthermore, in the above example, a steering device in which the steering member 410 and the rack shaft 480 are always mechanically connected is used as an example, but the present embodiment is not limited thereto. For example, the steering device according to the present embodiment may be a steer-by-wire type steering device. The contents described below in this specification may also be applied to steer-by-wire type steering devices.

[0048] The ECU 600 generally controls various electronic devices included in the vehicle 900. For example, the ECU 600 controls the magnitude of the assist torque or the reaction torque applied to the steering shaft 420 by adjusting the steering control amount provided to the torque applying portion 460.

[0049] Furthermore, ECU 600 controls opening and closing of a solenoid valve included in a hydraulic shock absorber included in suspension apparatus 100 by providing a suspension control amount to the solenoid valve. To achieve this control, a power line for supplying driving power from ECU 600 to the solenoid valve is arranged.

[0050] Vehicle 900 also includes a wheel speed sensor 320 installed for each wheel 300 and detecting the wheel speed of each wheel 300; a lateral G sensor 330 detecting the lateral acceleration of vehicle 900; a longitudinal G sensor 340 detecting the longitudinal acceleration of vehicle 900; a yaw rate sensor 350 detecting the yaw rate of vehicle 900; an engine torque sensor 510 detecting the torque generated by engine 500; an engine speed sensor 520 detecting the number of revolutions of engine 500; and a brake pressure sensor 530 detecting the pressure of the brake fluid applied to the brake device. The detection results of these various sensors are provided to ECU 600.

[0051] Although not shown, vehicle 900 includes: an anti-lock braking system (ABS), which is a system that prevents wheel locking during braking; a traction control system (TCS), which suppresses slip of the vehicle wheels during acceleration, etc.; and a vehicle stability assist (VSA) controllable braking device, which is a vehicle behavior stability control system equipped with an automatic braking function or a brake assist function for yaw moment control during cornering.

[0052] Here, the ABS, TCS, and VSA compare the wheel speeds determined based on the estimated vehicle body speed with the wheel speeds detected by wheel speed sensor 320. If the two wheel speeds differ by a predetermined value or more, the ABS, TCS, and VSA determine that the vehicle is in a slipping state. Through this process, the ABS, TCS, and VSA aim to stabilize the behavior of vehicle 900 by executing optimal braking control or traction control based on the vehicle's running state.

[0053] Furthermore, provision of detection results by the above-described various sensors to the ECU 600 and transmission of control signals from the ECU 600 to each portion are performed via a controller area network (CAN) 370 .

[0054] [Suspension control unit]

[0055] Hereinafter, the ECU 600 will be described in detail by changing the drawings. The ECU 600 includes a suspension control portion 650. The ECU 600 is one aspect of the suspension control device of the present embodiment.

[0056] The suspension control portion 650 refers to detection results of various sensors included in the CAN 370 and determines the size of the suspension control amount provided to the solenoid valve included in the hydraulic shock absorber included in the suspension device 100. The process of "determining the size of the control amount" includes a case where the size of the control amount is set to zero, that is, no control amount is provided.

[0057] Next, we will refer to Figure 2 The suspension control portion 650 will be described in more detail. Figure 2 is a block diagram showing an example of the functional configuration of the suspension control section 650 .

[0058] like Figure 2 As shown, the suspension control unit 650 includes a CAN input unit 660 , a vehicle state estimation unit 670 , a steering stability / ride comfort control unit 680 , and a control amount selection unit 690 .

[0059] The CAN input unit 660 obtains various signals via the CAN 370. For example, Figure 2 As shown, the CAN input unit 660 acquires the following signals (brackets indicate acquisition sources).

[0060] Wheel speeds of the four wheels (wheel speed sensors 320A to 320D)

[0061] Yaw angular velocity (yaw angular velocity sensor 350)

[0062] Front and rear G (front and rear G sensor 340)

[0063] Lateral G (lateral G sensor 330)

[0064] Brake pressure (brake pressure sensor 530)

[0065] Engine torque (engine torque sensor 510)

[0066] Engine speed (engine speed sensor 520)

[0067] Steering angle (steering angle sensor 440)

[0068] Steering torque (torque sensor 430)

[0069] The vehicle state estimation unit 670 estimates the state of the vehicle 900 by referring to various signals acquired by the CAN input unit 660. The vehicle state estimation unit 670 outputs the sprung speeds of the four wheels, the stroke speeds (suspension stroke speeds) of the four wheels, the pitch rate, the roll rate, the roll rate during cornering, and the pitch rate during acceleration / deceleration as estimation results.

[0070] like Figure 2 As shown, the vehicle state estimation unit 670 includes an acceleration / deceleration / steering correction amount calculation unit 671 , an acceleration / deceleration / steering pitch / roll rate calculation unit 673 , and a state estimation single wheel model application unit 674 .

[0071] The acceleration / deceleration / steering correction amount calculation unit 671 refers to the yaw angular velocity, front and rear G, the wheel speeds of the four wheels, the braking pressure, the engine torque and the engine speed, calculates the front and rear speeds of the vehicle body, the difference ratio between the inner and outer wheels and the adjustment gain, and then the acceleration / deceleration / steering correction amount calculation unit 671 provides the calculation results to the state estimation single wheel model application unit 674.

[0072] The acceleration / deceleration / steering pitch / roll rate calculation unit 673 calculates the roll rate during steering and the pitch rate during acceleration / deceleration with reference to the longitudinal G and the lateral G. The calculation results are provided to the steering stability / ride comfort control unit 680 .

[0073] The acceleration / deceleration / steering pitch / roll rate calculation unit 673 can be configured to further reference the suspension control variable output by the control variable selection unit 690. Furthermore, the roll rate value can be configured to use "0" as a reference value when the inclination of the vehicle 900 does not change within a predetermined minute, and the roll rate can be expressed as a deviation from the reference value. Furthermore, the acceleration / deceleration / steering pitch / roll rate calculation unit 673 can set a deadband of approximately ±0.5 in the roll rate during steering. Here, for example, "+" is marked on the left side of the vehicle 900 and "-" is marked on the right side.

[0074] State estimation single-wheel model application section 674 applies a single-wheel model for state estimation to each wheel, referring to the calculation results of acceleration / deceleration / steering correction amount calculation section 671. The model calculates the sprung speed, stroke velocity, pitch rate, and roll rate of the four wheels. The calculation results are provided to steering stability / ride comfort control section 680.

[0075] The steering stability / ride comfort control section 680 includes a skyhook control section 681 , a roll attitude control section 682 , a pitch attitude control section 683 , and an unsprung component control section 684 .

[0076] Skyhook control unit 681 performs ride comfort control (vibration suppression control) that suppresses vehicle shaking when riding on uneven road surfaces and enhances ride comfort. For example, skyhook control unit 681 determines a skyhook target control variable by referring to the sprung velocities, stroke velocities, pitch rates, and roll rates of the four wheels, and supplies the result to control variable selection unit 690.

[0077] More specifically, the skyhook control unit 681 sets a base damping force value by referring to a sprung damping force map based on sprung velocity. Furthermore, the skyhook control unit 681 calculates a skyhook target damping force by multiplying the set base damping force value by a skyhook gain. The skyhook target control amount is then determined based on the skyhook target damping force and the stroke velocity.

[0078] Roll attitude control unit 682 controls the roll attitude by calculating a roll attitude target control variable based on the roll rate during steering, a steering angle signal indicating the steering angle, and a steering torque signal indicating the steering torque. The calculated roll attitude target control variable is provided to control variable selection unit 690. The specific configuration of roll attitude control unit 682 will be described below.

[0079] The pitch attitude control unit 683 controls the pitch with reference to the pitch rate during acceleration and deceleration, determines a pitch target control amount, and provides the result to the control amount selection unit 690 .

[0080] The unsprung component control unit 684 controls the vibration suppression of the unsprung components of the vehicle 900 with reference to the wheel speeds of the four wheels, and determines the target control amount of the unsprung vibration suppression control. The determination result is provided to the control amount selection unit 690.

[0081] The control amount selection section 690 selects the target control amount having the highest value among the skyhook target control amount, the roll attitude target control amount, the pitch target control amount, and the unsprung vibration suppression control target control amount, and outputs the selected target control amount as the suspension control amount.

[0082] [Roll attitude control unit]

[0083] In the following, reference will be made to Figure 3 The roll attitude control section 682 will be described in more detail. Figure 3 : is a block diagram showing an example of the functional configuration of the roll attitude control section 682 according to the present embodiment. The roll attitude control section 682 calculates a roll attitude target control amount by referring to the roll angle signal, the actual pitch angle signal, the steering angle signal, the steering angular velocity signal, the roll rate signal, and the steering torque signal.

[0084] Here, in the case where the roll attitude control unit 682 refers to the roll angle signal, for example, the vehicle 900 may be configured to include a roll angle sensor, and the output from the roll angle sensor may be used as the roll angle signal, but the present invention is not limited thereto. For example, the roll rate calculated by the vehicle state estimation unit 670 may be configured to be integrated by the vehicle state estimation unit 670, and the roll angle obtained by the integration may be configured to be used as the roll angle signal.

[0085] In addition, when the roll attitude control unit 682 refers to the actual pitch angle signal, for example, the vehicle 900 may be configured to include a pitch angle sensor, and the output from the pitch angle sensor may be configured to be used as the pitch angle signal, but the present invention is not limited thereto. For example, the pitch rate calculated by the vehicle state estimation unit 670 may be configured to be integrated by the vehicle state estimation unit 670, and the pitch angle obtained by the integration may be configured to be used as the actual pitch angle signal.

[0086] In addition, in the case where the roll posture control unit 682 refers to the steering angular velocity signal, the steering angle signal output by the CAN input unit 660 can be configured to be differentiated by, for example, the steering stability / ride comfort control unit 680, and the steering angular velocity obtained by the differentiation can be configured to be used as a steering angular velocity signal.

[0087] Here, the roll attitude target controlled variable can be a target controlled variable that is a candidate for a suspension controlled variable. In other words, it is a target controlled variable that is referenced when controlling the damping force of the suspension. For example, the roll attitude target controlled variable calculated by the roll attitude control unit 682 can be the suspension controlled variable selected by the control variable selection unit 690. Therefore, it can be expressed as the roll attitude control unit 682 calculating the suspension controlled variable.

[0088] like Figure 3 As shown, the roll attitude control unit 682 includes a steering angle target control amount calculation unit 81, a steering angle velocity target control amount calculation unit 82, a roll rate target control amount calculation unit 83, a steering torque target control amount calculation unit 84, a steering torque velocity calculation unit 85, a steering torque velocity target control amount calculation unit 86, a steering torque derived target control amount selection unit 87, a roll attitude derived target control amount selection unit 88 and a roll attitude target control amount calculation unit 89.

[0089] The steering angle target control amount calculation unit 81 calculates the steering angle target control amount by referring to the steering angle indicated by the steering angle signal. The steering angular velocity target control amount calculation unit 82 calculates the steering angular velocity target control amount by referring to the steering angular velocity signal. Both the steering angle target control amount calculation unit 81 and the steering angular velocity target control amount calculation unit 82 refer to the steering angle signal to suppress the roll of the vehicle 900 and calculate the target control amounts so that the posture of the vehicle 900 becomes closer to being flat.

[0090] The roll rate target control amount calculation section 83 calculates the roll rate target control amount with reference to the roll rate at the time of steering supplied from the acceleration / deceleration / steering pitch / roll rate calculation section 673 .

[0091] The steering torque target control amount calculation unit 84 calculates the steering torque target control amount by referring to the steering torque signal indicated by the steering torque signal. The steering torque speed calculation unit 85 calculates the steering torque speed by referring to the time change of the steering torque indicated by the steering torque signal. The steering torque speed target control amount calculation unit 86 calculates the steering torque speed target control amount by referring to the steering torque speed calculated by the steering torque speed calculation unit 85 for each of the four wheels of the vehicle 900.

[0092] In this way, both the steering torque target control amount calculation unit 84 and the steering torque speed target control amount calculation unit 86 directly or indirectly refer to the steering torque signal to calculate the target control amount so that the roll of the vehicle 900 is suppressed and the posture of the vehicle 900 becomes closer to flat.

[0093] The steering torque-derived target controlled variable selection unit 87 selects a target controlled variable having a higher value between the steering torque target controlled variable and the steering torque speed target controlled variable as the steering torque-derived target controlled variable.

[0094] The roll attitude-derived target control amount selection unit 88 selects a target control amount having a higher value among the steering angle target control amount, the steering angular velocity target control amount, the roll rate target control amount, and the steering torque-derived target control amount as the roll attitude-derived target control amount.

[0095] (Roll attitude target control amount calculation unit)

[0096] The roll attitude target control amount calculation section 89 is an example of a target control amount calculation section described in the claims. The roll attitude target control amount calculation section 89 sets a target control amount referred to when controlling the damping force of the suspension to satisfy the following conditions.

[0097] The period of the phase of the roll angle of the vehicle 900 and the period of the phase of the pitch angle of the vehicle 900 are close to being in synchronization.

[0098] On the front wheel side of the vehicle 900, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side.

[0099] On the rear wheel side of the vehicle 900, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side.

[0100] Next, the suspension control method in this embodiment will be described.

[0101] Figure 4 1 is a block diagram showing an example of the functional configuration of the roll attitude target control amount calculation section 89 according to the present embodiment. Figure 4 As shown, the roll attitude target control amount calculation unit 89 includes a target pitch angle calculation unit 891 , a target differential damping gradient calculation unit 893 and a target control amount calculation unit 894 .

[0102] The target pitch angle calculation unit 891 calculates a target pitch angle with reference to a roll angle signal of the vehicle 900 . Figure 5 8 is a block diagram showing an example of the functional configuration of the target pitch angle calculation section according to the present embodiment. For example, the target pitch angle calculation section 891 includes an absolute value operation section 891 and a gain multiplication section 92, as shown in FIG. Figure 5 The absolute value operation section 91 calculates the absolute value of the roll angle indicated by the roll angle signal and supplies the calculated absolute value to the gain multiplication section 92. The gain multiplication section 92 calculates the target pitch angle by multiplying the absolute value of the roll angle supplied from the absolute value operation section 91 by a gain.

[0103] Target differential damping gradient calculation section 893 calculates target differential damping gradient ΔC by referring to the difference between the target pitch angle calculated by target pitch angle calculation section 891 and the actual pitch angle signal of vehicle 900. Therefore, according to this embodiment, more appropriate suspension control can be performed that quickly responds to changes in steering conditions.

[0104] Here, the target differential damping gradient ΔC has the following meaning: it is the front wheel side target differential damping gradient ΔC Front and the rear wheel side target differential damping gradient ΔC Rear The sum of , as can be seen from the description described below.

[0105] The target control amount calculation unit 894 calculates the roll attitude control amount with reference to the target differential damping gradient ΔC calculated by the target differential damping gradient calculation unit 893 . Figure 6 894 is a block diagram showing an example of the functional configuration of the target control amount operation section 894 according to the present embodiment. Figure 6 As shown, the target control amount calculation unit 894 includes a rear wheel side target control amount calculation unit 901, a front wheel side target control amount calculation unit 902 and a turning direction determination unit 903.

[0106] Turning direction determination unit 903 determines the turning direction of vehicle 900 by referring to the roll angle and roll rate obtained from vehicle state estimation unit 670. As described above, the roll angle referenced by turning direction determination unit 903 can be configured to be obtained from a roll angle sensor. Alternatively, the roll angle can be configured to be obtained by integrating the roll rate calculated by vehicle state estimation unit 670 using vehicle state estimation unit 670 and using the roll angle obtained by the integration as a roll angle signal. Turning direction determination unit 903 provides the determination result of the turning direction of vehicle 900 to rear wheel target control amount calculation unit 901 and front wheel target control amount calculation unit 902.

[0107] The rear wheel target control amount calculation unit 901 includes a limit DF storage unit (limit damping force storage unit) 904 , a rear wheel extension / contraction determination unit 905 , a subtraction unit 906 , an extension / contraction left / right conversion unit 907 , and a rear wheel target control amount calculation unit 908 .

[0108] The limit DF storage unit 904 stores the total value of the magnitude of the damping force on the extension side and the magnitude of the damping force on the contraction side. For example, the limit DF storage unit 904 stores the total value F of the magnitude of the damping force on the extension side and the magnitude of the damping force on the contraction side on the rear wheel side. Rear . The total value F Rear Provided to the subtraction unit 906.

[0109] The rear wheel side expansion and contraction determination unit 905 obtains the stroke speed STV of the rear left wheel 300C from the vehicle state estimation unit 670. RL and the stroke speed STV of the rear right wheel 300D RR .

[0110] The rear wheel side expansion and contraction determination unit 905 refers to the acquired stroke speed STV of the wheel 300C. RL and the stroke speed STV of the wheel 300D RR To determine which of the vehicle wheel 300C and the wheel 300D is the extension side and which is the contraction side.

[0111] Furthermore, the rear wheel side expansion and contraction determination unit 905 refers to the acquired stroke speed STV of the wheel 300C. RL and the stroke speed STV of the wheel 300D RR To calculate the contraction damping force F on the rear wheel side Rout The rear wheel side expansion and contraction determination unit 905 sets the contraction side damping force F Rout The data is supplied to the subtraction unit 906 and the scaling left / right conversion unit 907 .

[0112] The subtraction unit 906 refers to the total value F obtained from the limit DF 904. Rearand the contraction damping force F on the rear wheel side obtained from the rear wheel side expansion and contraction determination unit 905 Rout To calculate the extension side damping force F on the rear wheel side Rin The subtraction unit 906 converts the calculated extension damping force F on the rear wheel side into Rin Provided to the telescopic left / right conversion unit 907.

[0113] The telescopic left / right conversion unit 907 refers to the turning direction of the vehicle 900 obtained from the turning direction determination unit 903, the contraction side damping force F on the rear wheel side obtained from the rear wheel side telescopic determination unit 905, and the contraction side damping force F on the rear wheel side. Rout and the extension damping force F on the rear wheel side obtained from the subtraction unit 906 Rin To calculate the target damping force F of wheel 300C RL and the target damping force F of wheel 300D RR The telescopic left / right conversion unit 907 converts the calculated target damping force F of the wheel 300C into RL and the target damping force F of wheel 300D RR Provided to the rear wheel side target control amount calculation unit 908.

[0114] The rear wheel target control amount calculation unit 908 includes a rear wheel left target control amount calculation unit 909 and a rear wheel right target control amount calculation unit 910. In addition, the rear wheel target control amount calculation unit 908 obtains the stroke speed STV of the wheel 300C from the vehicle state estimation unit 670. RL and the stroke speed STV of the wheel 300D RR .

[0115] The rear wheel left target control amount calculation unit 909 calculates the target control amount of the wheel 300C based on the expansion and contraction of the suspension of the wheel 300C. More specifically, the rear wheel left target control amount calculation unit 909 refers to the stroke speed STV of the wheel 300C obtained from the vehicle state estimation unit 670. RL and the target damping force F of the wheel 300C obtained from the telescopic left / right conversion unit 907 RL To calculate the target control amount of the wheel 300C.

[0116] The rear wheel right target control amount calculation unit 910 calculates the target control amount of the wheel 300D based on the expansion and contraction of the suspension of the wheel 300D. More specifically, the rear wheel right target control amount calculation unit 910 refers to the stroke speed STV of the wheel 300D obtained from the vehicle state estimation unit 670. RR and the target damping force F of the wheel 300D obtained from the telescopic left / right conversion unit 907 RR To calculate the target control amount of the wheel 300D.

[0117] Therefore, according to the present embodiment, it is possible to perform more appropriate suspension control that quickly responds to changes in steering conditions.

[0118] The front wheel side target control amount calculation unit 902 includes a rear wheel right damping force calculation unit 911, a rear wheel left damping force calculation unit 912, a front wheel right damping force calculation unit 913, a front wheel left damping force calculation unit 914, multiplication and division units 915 to 918, a telescopic determination unit 919, a front wheel side target differential damping gradient calculation unit 920, a front wheel contraction side target damping gradient calculation unit 921 and a left-right conversion + target control amount calculation unit 922.

[0119] The rear wheel right damping force calculation unit 911 obtains the stroke velocity STV of the wheel 300D from the vehicle state estimation unit 670. RR , and obtains the actual control amount of the wheel 300D from the control amount selection unit 690 RR The rear wheel right damping force calculation unit 911 refers to the acquired stroke velocity STV of the wheel 300D. RR and the actual control amount of the wheel 300D RR , to calculate the damping force F of wheel 300D RR The rear wheel right damping force calculation unit 911 calculates the damping force F of the wheel 300D. RR The value is supplied to the multiplication and division unit 915. Here, the "actual control amount" is the control current supplied to the suspension of the wheel for suspension control.

[0120] The multiplication and division unit 915 refers to the stroke velocity STV of the wheel 300D acquired from the vehicle state estimation unit 670. RR and the damping force F of the wheel 300D obtained from the rear wheel right damping force calculation unit 911 RR , to calculate the damping gradient C on the right side of the rear wheel RR More specifically, the multiplication and division unit 915 divides the damping force F of the wheel 300D obtained from the rear wheel right damping force calculation unit 911 by RR Divide by the stroke velocity STV of the wheel 300D acquired from the vehicle state estimation unit 670 RR , to calculate the damping gradient C on the right side of the rear wheel RR The multiplication and division unit 915 calculates the damping gradient C of the right side of the rear wheel RR Provided to the expansion and contraction determination unit 919.

[0121] The rear wheel left damping force calculation unit 912 obtains the stroke velocity STV of the wheel 300C from the vehicle state estimation unit 670. RL and obtains the actual control amount of the wheel 300C from the control amount selection unit 690 RL The rear wheel left damping force calculation unit 912 refers to the acquired stroke velocity STV of the wheel 300C. RLand the actual control amount R of wheel 300C L , to calculate the damping force F of wheel 300C RL The rear wheel left damping force calculation unit 912 calculates the damping force F of the wheel 300C. RL Supplied to the multiplication and division unit 916.

[0122] The multiplication and division unit 916 refers to the stroke velocity STV of the wheel 300C acquired from the vehicle state estimation unit 670. RL and the damping force F of the wheel 300C obtained from the rear wheel left damping force calculation unit 912 RL To calculate the damping gradient C on the left side of the rear wheel RL More specifically, the multiplication and division unit 916 divides the damping force F of the wheel 300C obtained from the rear wheel left damping force calculation unit 912 by RL Divide by the stroke velocity STV of the wheel 300C acquired from the vehicle state estimation unit 670 RL , to calculate the damping gradient C on the left side of the rear wheel RL The multiplication and division unit 916 calculates the damping gradient C of the left rear wheel RL Provided to the expansion and contraction determination unit 919.

[0123] The front wheel right damping force calculation unit 913 obtains the stroke velocity STV of the front wheel 300B on the right side from the vehicle state estimation unit 670. FR and obtain the actual control amount from the control amount selection unit 690 FR The front wheel right damping force calculation unit 913 refers to the acquired stroke velocity STV of the wheel 300B. FR and the actual control amount of wheel 300B FR To calculate the damping force F of wheel 300B FR The front wheel right damping force calculation unit 913 calculates the damping force F of the wheel 300B. FR Supplied to the multiplication and division unit 917.

[0124] The multiplication and division unit 917 refers to the stroke velocity STV of the wheel 300B acquired from the vehicle state estimation unit 670. FR and the damping force F of the wheel 300B obtained from the front wheel right damping force calculation unit 913 FR , to calculate the damping gradient C on the right side of the front wheel FR More specifically, the multiplication and division unit 917 multiplies the damping force F of the wheel 300B obtained from the front wheel right damping force calculation unit 913 by FR Divide by the stroke velocity STV of the wheel 300B acquired from the vehicle state estimation unit 670 FR , to calculate the damping gradient C on the right side of the front wheel FR The multiplication and division unit 917 calculates the damping gradient C of the right side of the front wheel FRProvided to the expansion and contraction determination unit 919.

[0125] The front wheel left damping force calculation unit 914 obtains the stroke velocity STV of the front left wheel 300A from the vehicle state estimation unit 670. FL and obtains the actual control amount of the wheel 300A from the control amount selection unit 690 FL The front wheel left damping force calculation unit 914 refers to the acquired stroke velocity STV of the wheel 300A. FL and the actual control amount of wheel 300A FL , to calculate the damping force F of wheel 300A FL The front wheel left damping force calculation unit 914 calculates the damping force F of the wheel 300A. FL Provided to the multiplication and division unit 918.

[0126] The multiplication and division unit 918 refers to the stroke velocity STV of the wheel 300A acquired from the vehicle state estimation unit 670. FL and the damping force F of the wheel 300A obtained from the front wheel left damping force calculation unit 914 FL To calculate the damping gradient C on the left side of the front wheel FL More specifically, the multiplication and division unit 918 divides the damping force F of the wheel 300A obtained from the front wheel left damping force calculation unit 914 by FL Divide by the stroke velocity STV of the wheel 300A acquired from the vehicle state estimation unit 670 FL , to calculate the damping gradient C on the left side of the front wheel FL The multiplication and division unit 918 calculates the damping gradient C of the left side of the front wheel FL Provided to the expansion and contraction determination unit 919.

[0127] The expansion and contraction determination unit 919 refers to the turning direction of the vehicle 900 obtained from the turning direction determination unit 903, the damping gradient C obtained from the multiplication and division unit 915, and the RR and the damping gradient C obtained from the multiplication and division unit 916 RL , determine the damping gradient C RR and the damping gradient C RL Which of the following corresponds to the contraction side wheel damping gradient C on the rear wheel side? Rout , and determine the damping gradient C RR and the damping gradient C RL Which of the following corresponds to the extended side wheel damping gradient C on the rear wheel side? Rin The expansion and contraction determination unit 919 sets the determined contraction side wheel damping gradient C of the rear wheel side to Rout and the extended side wheel damping gradient C on the rear wheel side Rin The target differential damping gradient is provided to the front wheel side target differential damping gradient calculation unit 920 .

[0128] Furthermore, the expansion and contraction determination unit 919 refers to the turning direction of the vehicle 900 obtained from the turning direction determination unit 903, the damping gradient C obtained from the multiplication and division unit 917, and the damping gradient C obtained from the multiplication and division unit 917. FR and the damping gradient C obtained from the multiplication and division unit 918 FL , determine the front wheel side contraction side wheel damping gradient C Fout and the extended side wheel damping gradient C on the front wheel side Fin The expansion and contraction determination unit 919 sets the contraction side wheel damping gradient C on the front wheel side to Fout The left-right conversion + target control amount calculation unit 922 is provided, and the extension side wheel damping gradient C Fin The target damping gradient calculation unit 921 on the front wheel contraction side is provided with the target damping gradient calculation unit 921 on the front wheel contraction side.

[0129] The front wheel target differential damping gradient calculation section 920 includes a subtraction section 923 and a front wheel target damping gradient calculation section 924 . The front wheel target differential damping gradient calculation section 920 also acquires the target differential damping gradient ΔC from the target differential damping gradient calculation section 893 .

[0130] The subtraction unit 923 refers to the rear wheel extension side damping gradient C obtained from the extension determination unit 919. Rin and the damping gradient C on the rear wheel contraction side Rout To calculate the rear wheel side differential damping gradient ΔC Rear More specifically, the subtraction unit 923 reduces the damping gradient C from the rear wheel contraction side. Rout Subtract the damping gradient C on the extended side of the rear wheel Rin To calculate the rear wheel side differential damping gradient ΔC Rear The subtraction unit 923 converts the calculated rear wheel side differential damping gradient ΔC into Rear The target damping gradient is provided to the front wheel side target damping gradient calculation unit 924 .

[0131] The front wheel side target damping gradient calculation section 924 refers to the target differential damping gradient ΔC obtained from the target differential damping gradient calculation section 893 and the rear wheel side differential damping gradient ΔC obtained from the subtraction section 923. Rear , to calculate the front wheel side differential damping gradient ΔC Front Therefore, according to this embodiment, it is possible to perform more appropriate suspension control that quickly responds to changes in steering conditions. The front wheel side target damping gradient calculation unit 924 calculates the front wheel side differential damping gradient ΔC Front The target damping gradient calculation unit 921 on the front wheel contraction side is provided with the target damping gradient calculation unit 921 on the front wheel contraction side.

[0132] The front wheel contraction side target damping gradient calculation unit 921 refers to the damping gradient C of the extension side wheel acquired from the telescoping determination unit 919. Fin and the front wheel side differential damping gradient ΔC obtained from the front wheel side target damping gradient calculation unit 924 Front, to calculate the target damping gradient C of the extended wheel on the front wheel side Fout The front wheel retraction side target damping gradient calculation unit 921 calculates the front wheel extension side target damping gradient C Fout Provided to the left-right conversion + target control amount calculation unit 922.

[0133] The left-right conversion + target control amount calculation unit 922 refers to the turning direction of the vehicle 900 obtained from the turning direction determination unit 903, the contraction side wheel damping gradient C of the front wheel side obtained from the extension determination unit 919, and the rotation speed of the front wheel. Fout and the front wheel extension side target damping gradient C obtained from the front wheel contraction side target damping gradient calculation unit 921. Fout , calculates the target control amount of the extension side wheel on the front wheel side. Therefore, according to this embodiment, it is possible to perform more appropriate suspension control that quickly responds to changes in steering conditions.

[0134] Furthermore, the roll attitude target control amount calculation unit 89 according to the present embodiment can calculate the roll attitude target control amount corresponding to the actual situation of the vehicle 900 by calculating the damping force of each wheel 300 using the actual control amount of each wheel 300. As a result, according to the present embodiment, suspension control can be performed with higher accuracy.

[0135] (Suspension control method)

[0136] In the following, reference will be made to Figures 7 to 10 The suspension control method in the roll attitude target control amount calculation section 89 will be described. Figure 7 is a schematic diagram showing a mechanism for generating a pitching moment according to this embodiment. Figure 8 is a graph showing an example of the relationship between the damping force and the suspension stroke speed of the front and rear wheels according to the present embodiment. Figure 9 Schematic diagram showing the resultant of the damping forces of the left and right wheels on the rear wheel side according to the present embodiment. Figure 10 : is a flowchart showing the flow of the damping force control in this embodiment. Figure 11 is a graph showing the definition of the rear wheel side target differential damping gradient according to the present embodiment.

[0137] Hereinafter, among the state quantities indicating the state of the vehicle 900, the state quantity on the front wheel side and the state quantity on the rear wheel side can be indicated by adding reference letters "Front" and "Rear", respectively. In addition, in order to use the state quantity on the right side of the front wheel, the state quantity on the left side of the front wheel, the state quantity on the right side of the rear wheel, and the state quantity on the left side of the rear wheel, these can be indicated by adding reference letters "FR", "FL", "RR", and "RL", respectively. Moreover, when the vehicle 900 turns, the front wheel located on the inside of the turn, the front wheel located on the outside of the turn, the rear wheel located on the inside of the turn, and the rear wheel located on the outside of the turn can be indicated by adding reference letters "Fin", "Fout", "Rin", and "Rout", respectively.

[0138] First, when the driver turns the steering member 410, a steering torque is generated, and a steering torque signal is generated by the driver's turning operation of the steering member 410. The wheels 300A and 300B are turned to have a steering angle corresponding to the generated steering torque signal, and the vehicle 900 turns according to the steering angle.

[0139] When the vehicle 900 turns, due to the rolling motion, a damping force is generated according to the displacement speed of the shock absorber (front wheel side shock absorber and rear wheel side shock absorber), and a force that pushes the axle upward or downward is generated corresponding to the difference between the damping force on the extension side and the damping force on the contraction side.

[0140] Here, refer to Figure 10 , the control process of the damping force according to this embodiment is described.

[0141] (Step S11)

[0142] The roll attitude target control amount calculation unit 89 controls the damping forces of the wheels 300C and 300D to generate a force for pushing the axle upward in the rear wheel side shock absorber. More specifically, the roll attitude target control amount calculation unit 89 calculates the rear wheel side target control amount so that the resultant force F of the damping forces of the wheels 300C and 300D is Rear Becomes an upward force.

[0143] (Step S12)

[0144] Next, the roll attitude target control amount calculation unit 89 controls the damping forces of the wheels 300A and 300B to generate a force for pushing the axle downward in the front wheel side shock absorber. More specifically, the roll attitude target control amount calculation unit 89 calculates the front wheel side target control amount so that the resultant force F of the damping forces of the wheels 300A and 300B is Front Becomes a downward force.

[0145] Here, a method for controlling the damping forces of the wheels 300A, 300B, 300C, and 300D in the roll attitude target control amount calculation section 89 will be described by changing the drawings. Figure 8 As shown, for the same suspension stroke speed, the roll attitude target control amount calculation unit 89 changes the damping force F on the extension side of the wheel 300A and the wheel 300B to Fout The size of is controlled to be greater than the damping force F on the contraction side Fin In addition, if Figure 8 As shown, for the same suspension stroke speed, the roll attitude target control amount calculation unit 89 changes the damping force F on the contraction side of the wheel 300C and the wheel 300D to Rout The size of is controlled to be greater than the damping force F on the extension side Rin size.

[0146] As an example, Figure 9 As shown in FIG, when the vehicle 900 turns left, a damping force F on the extension side is generated on the wheel 300C on the inner side of the turn. Rin (F RL ), and a damping force F on the contraction side is generated on the wheel 300D on the outer side of the turn. Rout (F RR As described above, the roll attitude target control amount calculation unit 89 controls so that the damping force F on the contraction side Rout The magnitude is greater than the damping force F on the extension side Rin Therefore, the resultant force F of the damping forces of wheel 300C and wheel 300D during cornering is Rear It is the force pushing the axle upward.

[0147] On the contrary, when the vehicle 900 turns left, the damping force on the front wheel side is greater than the damping force F on the extension side. Fin (F FL ) is generated in the wheel 300A on the inner side of the turn, and the damping force F on the contraction side Fout (F FR ) is generated in the wheel 300B on the outer side of the turn. As described above, since the roll attitude target control amount calculation unit 89 controls so that the damping force F on the extension side Fin The magnitude is greater than the damping force F on the contraction side Fout The magnitude of the damping force of wheel 300A and wheel 300B during cornering is therefore the resultant force F Front This becomes a force that pushes the axle downward.

[0148] The roll attitude target control amount calculation section 89 controls so that the resultant force F of the damping forces of the wheel 300C and the wheel 300D during cornering is RearThe configuration of the force that pushes the axle upward is as described above, but the present embodiment is not limited thereto. As an example, the roll attitude target control amount calculation unit 89 may be configured so that the resultant force of the damping forces of the wheel 300C and the wheel 300D during cornering becomes zero. More specifically, the roll attitude target control amount calculation unit 89 controls so that, for the same suspension stroke speed, the damping force F on the contraction side of the wheel 300C and the wheel 300D is equal to zero. Rout The magnitude of the damping force F on the extension side Rin are the same size.

[0149] In this embodiment, as described above, the roll attitude target control amount calculation section 89 controls the damping forces of the wheels 300A, 300B, 300C, and 300D so that the pitching moment M is generated by the damping force difference between the front wheels and the rear wheels. y More specifically, if Figure 7 As shown, the axle on the front wheel side of the vehicle 900 is pushed downward, and the rear wheel side of the vehicle 900 is pushed upward, so that a pitching moment M is generated. y As a result, when vehicle 900 turns, a combined roll motion and pitch motion is generated in vehicle 900. Furthermore, the pitch angle of vehicle 900 can be easily generated, improving the responsiveness of vehicle 900 to control, and allowing the driver of vehicle 900 to feel a good turning sensation.

[0150] Furthermore, in this embodiment, control can be performed with reference to the roll angle and pitch angle to further improve cornering feel. For example, the suspension can be controlled to minimize the time difference between the peak of the roll angle and the peak of the pitch angle in vehicle 900. This control allows the driver of vehicle 900 to experience a good cornering feel.

[0151] More specifically, the target differential damping gradient calculation section 893 includes a pitching moment calculation section (not shown), and the target differential damping gradient calculation section 893 calculates the pitching moment with reference to the roll angle and pitch angle of the vehicle 900. The roll attitude target control amount calculation section 89 calculates a roll attitude target control amount such that the difference between the phase of the roll angle in the vehicle 900 and the phase of the pitch angle obtained based on the pitching moment is small, with reference to the roll angle of the vehicle 900 and the pitching moment calculated by the pitching moment calculation section.

[0152] Here, when the roll attitude target control amount calculation unit 89 calculates the roll attitude target control amount, the difference between the roll angle phase and the pitch angle phase can be appropriately set within a sufficiently small range to provide the driver with a good turning feel. From the perspective of providing the driver with a good turning feel, a smaller difference is more preferable. For example, it is preferably less than 1 / 4 cycle, more preferably less than 1 / 8 cycle, and most preferably zero. The "cycle" can be either the roll angle cycle or the pitch angle cycle, but from the perspective described above, the "cycle" is preferably the smaller of the roll angle cycle and the pitch angle cycle.

[0153] In other words, the roll attitude target control amount calculation unit 89 can be rephrased as calculating the target control amount so that the phase difference between the period of the roll angle of the vehicle 900 and the period of the pitch angle of the vehicle 900 is within a quarter cycle. Alternatively, the roll attitude target control amount calculation unit 89 can be rephrased as calculating the target control amount so that the phase difference between the period of the roll angle of the vehicle 900 and the period of the pitch angle of the vehicle 900 is within a eighth cycle. Furthermore, the roll attitude target control amount calculation unit 89 can be rephrased as calculating the target control amount so that the period of the roll angle of the vehicle 900 and the period of the pitch angle of the vehicle 900 are synchronized.

[0154] (ΔC of target differential damping gradient on the rear wheel side Rear Definition of

[0155] In the following, reference will be made to Figure 11 Describe the target differential damping gradient ΔC on the rear wheel side Rear The damping gradient C represents the slope of the graph showing the damping force versus the suspension stroke velocity. Figure 11 As shown, the target differential damping gradient ΔC on the rear wheel side Rear Indicates the contraction side wheel damping gradient C on the rear wheel side Rout The solid line indicates the extended side wheel damping gradient C on the rear wheel side. Rin The difference in slope between the dashed lines.

[0156] [Second embodiment]

[0157] Hereinafter, the second embodiment of the present invention will be described in detail. For the convenience of explanation, components having the same functions as those described in the above embodiment are given the same reference numerals, and their description will not be repeated.

[0158] This embodiment differs from the first embodiment in that a target pitch angle calculation unit 991 is provided instead of the target pitch angle calculation unit 891 . Figure 12This is a block diagram illustrating an example of the functional configuration of target pitch angle calculation unit 991 according to this embodiment. Target pitch angle calculation unit 991 calculates the target pitch angle by referring to a lateral G signal indicating the lateral acceleration of vehicle 900. More specifically, absolute value calculation unit 91 calculates the absolute value of the lateral G indicated by the lateral G signal and supplies the calculated absolute value to gain multiplication unit 92. Gain multiplication unit 92 calculates the target pitch angle by multiplying the absolute value of the lateral G supplied from absolute value calculation unit 91 by a gain. Therefore, according to this embodiment, more appropriate suspension control that promptly responds to changes in steering conditions can be implemented.

[0159] [Third embodiment]

[0160] Hereinafter, a third embodiment of the present invention will be described in detail. For convenience of explanation, components having the same functions as those described in the above embodiments are given the same reference numerals, and description thereof will not be repeated.

[0161] The present embodiment differs from the first embodiment in that a target pitch angle calculation unit 1091 is provided instead of the target pitch angle calculation unit 891 . Figure 13 Target pitch angle calculation unit 1091 is a block diagram illustrating an example of the functional configuration of target pitch angle calculation unit 1091 according to this embodiment. Target pitch angle calculation unit 1091 includes a gain multiplication unit 95 instead of gain multiplication unit 92. Target pitch angle calculation unit 1091 also includes a gain setting unit 96. In these respects, target pitch angle calculation unit 1091 differs from target pitch angle calculation unit 891 in the first embodiment. Gain multiplication unit 95 and gain multiplication unit 96 form a gain changing unit.

[0162] Gain setting unit 96 sets a gain value by referring to at least one of a lateral G signal indicating the lateral acceleration of vehicle 900 and a longitudinal G signal indicating the longitudinal acceleration of vehicle 900. Gain multiplication unit 95 refers to the gain value set by gain setting unit 96 and changes the gain to be multiplied according to the gain value. Gain multiplication unit 95 then calculates a target pitch angle by multiplying the absolute value of the roll angle calculated by absolute value calculation unit 91 by the changed gain.

[0163] When the road surface is uneven, the unevenness causes the lateral G and fore-aft G of vehicle 900 to fluctuate directly or indirectly through steering torque, etc. Therefore, from the perspective of performing suspension control that appropriately reflects the road surface conditions, it is advantageous to refer to the lateral G and fore-aft G of vehicle 900 to calculate the target pitch angle.

[0164] [Example implemented by software]

[0165] The control block (roll attitude target control amount calculation section 89 ) of the ECU 600 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software using a central processing unit (CPU).

[0166] In the latter case, ECU600 includes: a CPU that executes instructions of a program that is software that realizes each function; a read-only memory (ROM) or a storage device (referred to as a "recording medium"), in which the above-mentioned program and various data are recorded in a manner readable by a computer (or CPU); a random access memory (RAM), into which the above-mentioned program is loaded; and the like. Then, the purpose of the present invention is achieved by the computer (or CPU) reading the above-mentioned program from the recording medium and executing the program. As the above-mentioned recording medium, "non-temporary tangible media" such as magnetic tapes, disks, cards, semiconductor memories, programmable logic circuits, etc. can be used. In addition, the above-mentioned program can be provided to the computer via any transmission medium (communication network, broadcast waves, etc.) that can transmit the program. The present invention can also be implemented in the form of a data signal embedded in a carrier wave, in which the above-mentioned program is implemented by electronic transmission.

[0167] [Additional Notes]

[0168] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. In addition, the technical scope of the present invention includes embodiments obtained by appropriately combining the technical means disclosed in different embodiments.

Claims

1. A suspension control device configured to control a damping force of a suspension of a vehicle, the suspension control device comprising: a target control amount calculation unit configured to set a target control amount to be referred to when controlling the damping force of the suspension, such that: A phase cycle of the roll angle of the vehicle and a phase cycle of the pitch angle of the vehicle are close to a synchronous state; On the front wheel side of the vehicle, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side, and On the rear wheel side of the vehicle, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side, wherein, The target control amount calculation unit includes: a target pitch angle calculation unit configured to calculate a target pitch angle with reference to a roll angle signal of the vehicle, a target differential damping gradient calculation section configured to calculate a target differential damping gradient with reference to the target pitch angle and an actual pitch angle signal of the vehicle, and a front wheel side target differential damping gradient calculation unit configured to calculate a front wheel side target differential damping gradient with reference to a rear wheel side differential damping gradient and the target differential damping gradient, wherein the rear wheel side differential damping gradient is calculated based on respective actual damping gradients in the contraction-side wheel and the extension-side wheel on the rear wheel side.

2. The suspension control device according to claim 1, wherein: The target control amount calculation unit includes: a rear wheel side expansion and contraction determination section configured to determine expansion and contraction of each of the suspensions of the left and right wheels on the rear wheel side with reference to each of the suspension stroke speeds of the left and right wheels on the rear wheel side, and A rear wheel target control amount calculation unit is configured to calculate target control amounts for the left and right wheels on the rear wheel side based on expansion and contraction of the suspensions of the left and right wheels on the rear wheel side.

3. The suspension control device according to claim 1 or 2, wherein: The target pitch angle calculation unit includes: a gain multiplication section configured to calculate the target pitch angle by multiplying the roll angle signal by a gain, and A gain setting unit is configured to set a value of the gain with reference to the lateral acceleration or the longitudinal acceleration.

4. The suspension control device according to claim 1, wherein: The target control amount calculation unit includes: a front wheel contraction-side target damping gradient calculation section configured to calculate a target damping gradient of the contraction-side wheel on the front wheel side with reference to the front wheel-side target differential damping gradient and an actual damping gradient of the extension-side wheel on the front wheel side.

5. A suspension control device configured to control a damping force of a suspension of a vehicle, the suspension control device comprising: a target control amount calculation unit configured to set a target control amount to be referred to when controlling the damping force of the suspension, such that: A phase cycle of the roll angle of the vehicle and a phase cycle of the pitch angle of the vehicle are close to a synchronous state; On the front wheel side of the vehicle, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side, and On the rear wheel side of the vehicle, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side, wherein, The target control amount calculation unit includes: a target pitch angle calculation unit configured to calculate the target pitch angle with reference to a lateral acceleration of the vehicle, a target differential damping gradient calculation section configured to calculate a target differential damping gradient with reference to the target pitch angle and an actual pitch angle signal of the vehicle, and a front wheel side target differential damping gradient calculation unit configured to calculate a front wheel side target differential damping gradient with reference to a rear wheel side differential damping gradient and the target differential damping gradient, wherein the rear wheel side differential damping gradient is calculated based on respective actual damping gradients in the contraction-side wheel and the extension-side wheel on the rear wheel side.

6. The suspension control device according to claim 5, wherein: The target control amount calculation unit includes: a rear wheel side expansion and contraction determination section configured to determine expansion and contraction of each of the suspensions of the left and right wheels on the rear wheel side with reference to each of the suspension stroke speeds of the left and right wheels on the rear wheel side, and A rear wheel target control amount calculation unit is configured to calculate target control amounts for the left and right wheels on the rear wheel side based on expansion and contraction of the suspensions of the left and right wheels on the rear wheel side.

7. The suspension control device according to claim 5, wherein: The target control amount calculation unit includes: a front wheel contraction-side target damping gradient calculation section configured to calculate a target damping gradient of the contraction-side wheel on the front wheel side with reference to the front wheel-side target differential damping gradient and an actual damping gradient of the extension-side wheel on the front wheel side.

8. A suspension device comprising: Vehicle suspension; as well as A control unit configured to control the damping force of the suspension, wherein: The control portion includes a target control amount calculation portion configured to set a target control amount referred to when controlling the damping force of the suspension, such that: The cycle of the phase of the roll angle of the vehicle and the cycle of the phase of the pitch angle of the vehicle are close to a synchronous state; On the front wheel side of the vehicle, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side; and On the rear wheel side of the vehicle, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side, The target control amount calculation unit includes: a target pitch angle calculation unit configured to calculate the target pitch angle with reference to a lateral acceleration of the vehicle, a target differential damping gradient calculation section configured to calculate a target differential damping gradient with reference to the target pitch angle and an actual pitch angle signal of the vehicle; and a front wheel side target differential damping gradient calculation unit configured to calculate a front wheel side target differential damping gradient with reference to a rear wheel side differential damping gradient and the target differential damping gradient, wherein the rear wheel side differential damping gradient is calculated based on respective actual damping gradients in the contraction-side wheel and the extension-side wheel on the rear wheel side.

9. A suspension device comprising: Vehicle suspension; as well as A control unit configured to control the damping force of the suspension, wherein: The control portion includes a target control amount calculation portion configured to set a target control amount referred to when controlling the damping force of the suspension, such that: The cycle of the phase of the roll angle of the vehicle and the cycle of the phase of the pitch angle of the vehicle are close to a synchronous state; On the front wheel side of the vehicle, the magnitude of the damping force on the extension side is greater than the magnitude of the damping force on the contraction side; and On the rear wheel side of the vehicle, the magnitude of the damping force on the contraction side is equal to or greater than the magnitude of the damping force on the extension side, The target control amount calculation unit includes: a target pitch angle calculation unit configured to calculate the target pitch angle with reference to a lateral acceleration of the vehicle, a target differential damping gradient calculation section configured to calculate a target differential damping gradient with reference to the target pitch angle and an actual pitch angle signal of the vehicle, and a front wheel side target differential damping gradient calculation unit configured to calculate a front wheel side target differential damping gradient with reference to a rear wheel side differential damping gradient and the target differential damping gradient, wherein the rear wheel side differential damping gradient is calculated based on respective actual damping gradients in the contraction-side wheel and the extension-side wheel on the rear wheel side.

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