Electrically powered suspension device

Abstract

Provided is an electric suspension device that can exhibit a comfortable ride feeling with a sense of oneness with the vehicle even when turning in a moving driving situation. The electric suspension device includes an electromagnetic actuator provided between a vehicle body and a wheel of a vehicle, which generates a load for attenuating vibration of the vehicle body; an information acquisition unit that acquires information on a sprung state quantity of the vehicle and a driving road surface state; a target load calculation unit that calculates a first target load related to skyhook control based on the sprung state quantity and a second target load related to preview control based on the driving road surface state; and a load control unit that performs load control of the electromagnetic actuator. The target load calculation unit further calculates a third target load related to roll generation control based on a target roll angle, and performs calculation of a combined target load that combines the first and second target loads and the third target load. The load control unit performs load control of the electromagnetic actuator using the combined target load.

Description

TECHNICAL FIELD

[0001] The present application relates to an electric suspension device provided with an actuator that is provided between a vehicle body and a wheel of a vehicle and generates a load for attenuating a vibration of the vehicle body. BACKGROUND

[0002] Conventionally, an electric suspension device provided with an actuator that is provided between a vehicle body and a wheel of a vehicle and generates a load for attenuating a vibration of the vehicle body is known (for example, refer to Patent Literature 1).

[0003] The electric suspension device of Patent Literature 1 is provided with a control device that performs control of a control target capable of controlling an output of a system that outputs an influence of a disturbance input with a time lag. The control device generates a control command that eliminates the influence of the disturbance from the output based on a transfer function from the input of the disturbance to the output of the system, a transfer function from a control command of the control target output to the control system to the output, and disturbance information input to the system.

[0004] According to the electric suspension device of Patent Literature 1, the control device operates in a manner that cancels a vibration of the vehicle body generated based on a road surface input, and thus it is possible to suppress the vibration of the vehicle body.

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2018-134899 SUMMARY

[0006] In addition, for example, in a case where sporty driving is performed, there is a case where a driver estimates a slip-out timing of a tire provided in the own vehicle by perceiving a roll behavior generated in a turning of the vehicle.

[0007] However, in the electric suspension device of Patent Literature 1, the control device originally operates in a manner that suppresses a roll behavior generated in a turning of the vehicle, regardless of whether or not sporty driving is performed. Thus, in a case where the sporty driving is performed while the turning is being performed, the driver cannot estimate the slip-out timing of the tire based on the roll behavior. Therefore, there is a concern that the sense of oneness in the sporty driving is impaired. As a result, there is a concern that the driver feels a sense of incongruity.

[0008] The present application has been made in view of the above-described circumstances, and an object thereof is to provide an electric suspension device that can exhibit a comfortable ride feeling along with a sense of oneness even in a case where sporty driving is performed while a turning is being performed.

[0009] In order to achieve the above-mentioned object, the electric suspension device of the present invention (1) comprises: an actuator, which is provided between a vehicle body and a wheel, and generates a load for attenuating the vibration of the vehicle body; an information acquisition unit, which acquires information on the sprung state quantity and the state of the road surface on which the vehicle is traveling; and a target load calculation unit, which calculates a target load related to skyhook control based on the sprung state quantity. and a load control unit for performing load control on the actuator using a calculation result of the target load calculation unit. The electric suspension device is characterized in that the information acquisition unit further acquires operating information related to the acceleration and deceleration and steering angle of the vehicle, and further includes a target roll angle derivation unit that derives the target roll angle of the vehicle based on the operating information. The target load calculation unit further calculates a third target load related to roll generation control based on the target roll angle derived by the target roll angle derivation unit, and performs calculation of a combined target load that combines the first target load, the second target load, and the third target load. The load control unit uses the combined target load to control the load of the actuator.

[0010] Effects of the Invention

[0011] According to the present invention, a comfortable ride accompanied by a sense of unity between the driver and the vehicle can be achieved even during steering in a sporty driving situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing the overall configuration of an electric suspension device according to an embodiment of the present invention.

[0013] Figure 2 It is a partial cross-sectional view of an electromagnetic actuator included in the electric suspension device according to the embodiment of the present invention.

[0014] Figure 3 It is a structural diagram of the interior and peripheral parts of a load control ECU included in the electric suspension device according to the embodiment of the present invention.

[0015] Figure 4 This is a diagram conceptually showing the internal structure of a load control ECU included in the electric suspension device according to the embodiment of the present invention.

[0016] Figure 5 These are diagrams for explaining the operation of the electric suspension device according to the embodiment of the present invention.

[0017] Figure 6 This is a flowchart for explaining the operation of the electric suspension device according to the embodiment of the present invention.

[0018] Description of Reference Numerals

[0019] 10 vehicle

[0020] 11 electric suspension device

[0021] 13 electromagnetic actuator (actuator)

[0022] 41 information acquisition section

[0023] 43 target load calculation section

[0024] 45 load control section

[0025] 61 target roll angle derivation section

[0026] 63 vehicle state estimation section (information acquisition section)

[0027] 65 first subtraction section (spring-on state quantity correction section)

[0028] 71 first target load calculation section (target load calculation section)

[0029] 73 second target load calculation section (target load calculation section)

[0030] 75 third target load calculation section (target load calculation section)

[0031] 77 combination section (target load calculation section)

[0032] θ target roll angle DETAILED DESCRIPTION

[0033] An electric suspension device 11 of an embodiment of the present application will be described in detail below with appropriate reference to the drawings.

[0034] Further, in the drawings shown below, common reference numerals are assigned to components having common functions. In this case, as a principle, repeated description is omitted. In addition, there are cases in which the sizes and shapes of components are deformed or exaggerated for the purpose of explanation.

[0035] [Common basic structure in electric suspension device 11 of embodiment of the present application]

[0036] First, with reference to Figure 1 , Figure 2 the common basic structure in the electric suspension device 11 of the embodiment of the present application will be described.

[0037] Figure 1 is a general structural view common to the electric suspension device 11 of the embodiment of the present application. Figure 2 is a partial cross-sectional view of an electromagnetic actuator 13 that constitutes a part of the electric suspension device 11.

[0038] AsFigure 1 As shown, the electric suspension device 11 according to the embodiment of the present invention is configured to include a plurality of electromagnetic actuators 13 provided for each wheel of a vehicle (sometimes referred to as the subject vehicle) 10, and a load control ECU 15. The plurality of electromagnetic actuators 13 and the load control ECU 15 are connected via power supply lines 14 (see FIG. Figure 1 solid line) and signal line 16 (see Figure 1 The power supply line 14 is used to supply load control power from the load control ECU 15 to the plurality of electromagnetic actuators 13, and the signal line 16 is used to send the electric motor 31 (refer to Figure 2 ) load control signal.

[0039] In this embodiment, four electromagnetic actuators 13 are provided for each wheel, including the front wheels (left front wheel and right front wheel) and the rear wheels (left rear wheel and right rear wheel). The electromagnetic actuators 13 provided for each wheel are independently load-controlled according to the extension and contraction operation of each wheel.

[0040] In the embodiment of the present invention, unless otherwise specified, the plurality of electromagnetic actuators 13 have a common structure. Therefore, the structure of one electromagnetic actuator 13 will be described instead of describing the plurality of electromagnetic actuators 13 .

[0041] like Figure 2 As shown, the electromagnetic actuator 13 includes a base housing 17 , an outer tube 19 , a ball bearing 21 , a ball screw shaft 23 , a plurality of balls 25 , a nut 27 , and an inner tube 29 .

[0042] The base housing 17 rotatably supports the base end of the ball screw shaft 23 via a ball bearing 21. The outer tube 19 is provided on the base housing 17 and houses the ball screw mechanism 18, which includes the ball screw shaft 23, a plurality of balls 25, and a nut 27. The balls 25 roll along the screw grooves of the ball screw shaft 23. The nut 27 engages with the ball screw shaft 23 via the balls 25, converting the rotational motion of the ball screw shaft 23 into linear motion. The inner tube 29, connected to the nut 27, is integral with the nut 27 and displaces axially along the outer tube 19.

[0043] In order to transmit the rotational driving force to the ball screw shaft 23, as shown in FIG. Figure 2 As shown, the electromagnetic actuator 13 includes an electric motor 31, a pair of pulleys 33, and a belt member 35. The electric motor 31 is provided in parallel with the outer tube 19 in the base housing 17. The pulleys 33 are attached to the motor shaft 31a of the electric motor 31 and the ball screw shaft 23, respectively. The belt member 35 is suspended from the pair of pulleys 33 to transmit the rotational driving force of the electric motor 31 to the ball screw shaft 23.

[0044] The electric motor 31 is provided with a resolver 37 that detects a rotation angle signal of the electric motor 31. The rotation angle signal of the electric motor 31 detected by the resolver 37 is transmitted to the load control ECU 15 via a signal line 16. The electric motor 31 is rotationally controlled based on the load control power supplied by the load control ECU 15 to each of the plurality of electromagnetic actuators 13 via a power supply line 14.

[0045] In addition, in this embodiment, if Figure 2 As shown, by adopting a layout in which the motor shaft 31a of the electric motor 31 and the ball screw shaft 23 are arranged substantially parallel to each other and connected to each other, the axial dimension of the electromagnetic actuator 13 is shortened. However, a layout in which the motor shaft 31a of the electric motor 31 and the ball screw shaft 23 are arranged coaxially and connected to each other may also be adopted.

[0046] In the electromagnetic actuator 13 of the embodiment of the present invention, as Figure 2 As shown, a connecting portion 39 is provided at the lower end of the base shell 17. The connecting portion 39 is connected and fixed to the unsprung member 81 (lower arm, steering knuckle, etc. on the wheel side, see Figure 5 On the other hand, the upper end portion 29a of the inner tube 29 is connected and fixed to the sprung member 83 (the strut tower portion on the vehicle body side, etc., see Figure 5 ).

[0047] In short, the electromagnetic actuator 13 and the spring member 85 (see FIG. 1 ) provided between the sprung member (vehicle body) 83 and the unsprung member (wheels etc. with tires mounted thereon, hereinafter collectively referred to as “wheels etc.”) 81 of the vehicle 10. Figure 5 ) are arranged in parallel. The electromagnetic actuator 13 acts as a virtual shock absorber 87 (refer to Figure 5 )’s role.

[0048] like Figure 5 As shown, the unsprung members (wheels, etc.) 81 provided on the left and right wheels are connected to each other via, for example, a U-shaped stabilizer 89 .

[0049] A spring component 91 and a damper component 93 are interposed between an unsprung member (wheel, etc.) 81 of the vehicle 10 and the road surface. The tires mounted on the wheels of the vehicle 10 function as the spring component 91 and the damper component 93.

[0050] The electromagnetic actuator 13 configured as described above operates as follows. For example, consider a case where a pushing force related to upward vibration is input to the link portion 39 from the wheel side of the vehicle 10. In this case, the inner tube 29 and the nut 27 will be lowered integrally with respect to the outer tube 19 to which the pushing force related to upward vibration is applied. Influenced by this, the ball screw shaft 23 will rotate in a direction in accordance with the lowering of the nut 27. At this time, a rotational drive force of the electric motor 31 that hinders the lowering of the nut 27 in the direction is generated. This rotational drive force of the electric motor 31 is transmitted to the ball screw shaft 23 via the belt member 35.

[0051] As such, the electromagnetic actuator 13 attenuates the vibration to be transmitted from the wheel side to the vehicle body side by causing a reaction force (attenuation force) against the pushing force related to upward vibration to act on the ball screw shaft 23.

[0052] [Internal structure of load control ECU 15]

[0053] Next, the internal and peripheral structures of the load control ECU 15 included in the electric suspension device 11 of the embodiment of the present application will be described with reference to Figure 3 The internal and peripheral structures of the load control ECU 15 included in the electric suspension device 11 of the embodiment of the present application will be described with reference to

[0054] Figure 3 is a structure diagram of the internal and peripheral structures of the load control ECU 15 included in the electric suspension device 11 of the embodiment of the present application.

[0055] [Electric suspension device 11 of the embodiment of the present application]

[0056] The load control ECU 15 included in the electric suspension device 11 of the embodiment of the present application is configured to include a microcomputer that performs various arithmetic processes. The load control ECU 15 has a load control function and performs load control of a plurality of the electromagnetic actuators 13 based on a rotational angle signal including a stroke position of the electric motor 31 detected by the resolver 37, a merging target load (details will be described later), a motor current applied to the electric motor 31, and the like, thereby generating a load related to the attenuation operation and the extension / contraction operation of the electromagnetic actuator 13.

[0057] To realize such a load control function, as shown in Figure 3 the load control ECU 15 is configured to include an information acquisition portion 41, a target load arithmetic portion 43, and a load control portion 45.

[0058] As shown in Figure 3As shown, the information acquisition unit 41 acquires time-series information on the steering angle and vehicle speed. The steering angle information can be acquired using a steering angle sensor 51 that detects the steering angle of a steering wheel (not shown) provided in the vehicle 10. Vehicle speed information can be acquired using a vehicle speed sensor 53. Alternatively, the degree of depression of the accelerator pedal or the degree of depression of the brake pedal can be referenced as vehicle speed information.

[0059] Furthermore, the information acquisition unit 41 acquires a preview image and vehicle height information as time-series information regarding the road surface conditions in the direction of travel of the vehicle 10. The preview image information can be acquired, for example, by using a camera 42 mounted on the vehicle 10 or by using external sensors such as radar or lidar. Furthermore, the vehicle height information can be acquired, for example, by using a vehicle height sensor 55 that detects the height of the vehicle 10.

[0060] The information acquisition unit 41 acquires time series information on each of the sprung acceleration and the unsprung acceleration. The sprung acceleration information can be acquired based on the detection values ​​of the sprung acceleration sensor 57 provided on the sprung member (vehicle body) 83 of the vehicle 10. Furthermore, the unsprung acceleration information can be acquired based on the detection values ​​of the unsprung acceleration sensor 59 provided on the unsprung member (wheel, etc.) 81 of the vehicle 10.

[0061] The information acquired by the information acquisition unit 41 , including the steering angle, vehicle speed, preview image, vehicle height, sprung acceleration, unsprung acceleration, stroke position of the electromagnetic actuator 13 , and motor current of the electric motor 31 , is sent to the target load calculation unit 43 .

[0062] like Figure 3 As shown, the target load calculation unit 43 has a function of calculating, based on the various information obtained by the information acquisition unit 41 , a target value related to the damping operation and the extension and contraction operation of the electromagnetic actuator 13 , that is, a combined target load.

[0063] In practice, the target load calculation unit 43 includes a first target load calculation unit 71 for calculating a first target load related to skyhook control, a second target load calculation unit 73 for calculating a second target load related to look-ahead control, and a third target load calculation unit 75 for calculating a third target load related to roll generation control. The structures of the first target load calculation unit 71, the second target load calculation unit 73, and the third target load calculation unit 75 will be described in detail later.

[0064] The load control section 45 calculates a target current value that enables the combined target load calculated by the target load calculation section 43. Next, the load control section 45 performs drive control of the electric motors 31 included in the plurality of electromagnetic actuators 13 in such a manner that the motor current associated with the electric motors 31 follows the calculated target current value. The load control of the respective electric motors 31 is performed independently in the plurality of electromagnetic actuators 13.

[0065] [Main part structure of the load control ECU 15 included in the electric suspension device 11]

[0066] Next, the internal structure of the load control ECU 15 included in the electric suspension device 11 according to the embodiment of the present application will be described with appropriate reference to Figure 4 , Figure 5 .

[0067] Figure 4 is a conceptual diagram that conceptually shows the internal structure of the load control ECU 15 included in the electric suspension device 11 according to the embodiment of the present application. Figure 5 is a diagram for explaining the operation of the electric suspension device 11.

[0068] As shown in Figure 4 , the load control ECU 15 included in the electric suspension device 11 includes a target roll angle derivation section 61, a vehicle state estimation section 63, a first subtraction section 65, a second subtraction section 67, a first target load calculation section 71, a second target load calculation section 73, a third target load calculation section 75, and a combination section 77. The vehicle state estimation section 63 simultaneously assumes the role of the information acquisition section 41. The first target load calculation section 71, the second target load calculation section 73, and the third target load calculation section 75 are included in the target load calculation section 43.

[0069] The target roll angle derivation section 61 is configured to include a lateral acceleration calculation section 68 and a target roll angle calculation section 69.

[0070] Here, as shown in Figure 5 , the derivation of the target roll angle in the target roll angle derivation section 61 is performed using a motion equation (see Equation (1)) of roll motion that includes the damping coefficients Cs (C sR , C sL : C sR is the damping coefficient of the right-side virtual shock absorber 87, and C sL is the damping coefficient of the left-side virtual shock absorber 87. The same applies hereinafter) of the virtual shock absorbers 87 included in the electromagnetic actuators 13 respectively provided at the four wheels of the vehicle 10.

[0071] [Equation 1]

[0072]

[0073] In formula (1), J B represents the roll inertia moment of the sprung member (vehicle body) 83, M B represents the mass of the vehicle body 83, L represents half the length of the wheelbase of the vehicle 10, K s (K sR , K sL ) represents the spring constant of the spring member (suspension) 85, θ represents the roll angle of the vehicle body 83 (θ″ represents the roll angular acceleration of the vehicle body 83), y represents the lateral displacement of the vehicle body 83 (y″ represents the lateral acceleration of the vehicle body 83), h represents the distance from the roll center to the center of gravity of the vehicle body 83, and x t (x tR , x tL ) represents the vertical displacement of the unsprung member (wheel, etc.) 81, x B (x BR , x BL ) represents the vertical displacement of the vehicle body 83, F R represents the thrust (load) of the right electromagnetic actuator 13, F L It shows the thrust (load) of the left electromagnetic actuator 13.

[0074] In addition, Figure 5 In, M t represents the mass of the wheel, etc., x r (x rR 、x rL ) represents the road height input, K t represents the spring constant of the unsprung member (tire) 81 (the spring constant of the tires of the four wheels is set to a common value), C t The damping coefficient of the unsprung member (tire) 81 is shown (the damping coefficients of the tires of the four wheels are set to a common value).

[0075] The lateral acceleration calculation unit 68 calculates the lateral acceleration (y″) of the vehicle body using the following equation (2) based on the time series information of the steering angle and vehicle speed of the host vehicle 10 acquired by the information acquisition unit 41 .

[0076] [Formula 2]

[0077]

[0078] In formula (2), A is the stability coefficient, v is the vehicle speed, and δ is the steering angle.

[0079] The relationship between the lateral acceleration (y") and the steering angle (δ) is derived using equation (2).

[0080] The lateral acceleration (y″) of the vehicle body calculated by the lateral acceleration calculation unit 68 is sent to the target roll angle calculation unit 69 .

[0081] The target roll angle calculation unit 69 calculates a target roll angle θ of the vehicle body based on the lateral acceleration (y″) of the vehicle body calculated by the lateral acceleration calculation unit 68 .

[0082] Specifically, the Laplace transform is performed on the equation (1) related to the above-mentioned rolling motion equation. For convenience, if the road surface input x r (x rR 、x rL ) is assumed to be zero (no unevenness in the road surface), and the vertical displacement of the unsprung member (wheel, etc.) 81 is x t (x tR 、x tL ) is assumed to be zero, the target roll angle θ of the vehicle body can be expressed by the following equation (3). t The motion model used here assumes movement without road input, so for convenience, it is assumed to be zero. Therefore, if the motion model to be adopted assumes movement with road input, then an appropriate value can be set as the road displacement.

[0083] [Formula 3]

[0084]

[0085] In formula (3), s is the Laplace operator.

[0086] Information on the target roll angle θ of the host vehicle 10 (the vehicle body) calculated by the target roll angle calculation unit 69 is sent to each of the first subtraction unit 65 and the third target load calculation unit 75 .

[0087] The vehicle state estimation unit 63 estimates, based on the time series information of the sprung acceleration and the unsprung acceleration acquired by the information acquisition unit 41, the vehicle state quantity at the current point in time, for example, the "sprung velocity" as a first vehicle state quantity (sprung state quantity) and the second vehicle state quantity (the time integral value of the sprung velocity).

[0088] The first vehicle state quantity (sprung velocity) and the second vehicle state quantity (time-integrated value of the sprung velocity) estimated by the vehicle state estimation unit 63 are sent to the first subtraction unit 65 and the second subtraction unit 67 , respectively.

[0089] The first subtraction section 65 subtracts the target roll angle velocity of the host vehicle 10 calculated by the target roll angle calculation section 69 from the current first vehicle state quantity (sprung mass velocity) estimated by the vehicle state estimation section 63. Thus, the correction of the first vehicle state quantity (sprung mass velocity) is performed by removing the roll angle velocity component from the current first vehicle state quantity (sprung mass velocity). The first subtraction section 65 corresponds to the "sprung mass state quantity correction section" of the present application.

[0090] The first vehicle state quantity (sprung mass velocity) corrected by the first subtraction section 65 is sent to the first target load calculation section 71.

[0091] The second subtraction section 67 subtracts the current second vehicle state quantity (time integral value of sprung mass velocity) estimated by the vehicle state estimation section 63 from the current vehicle height acquired by the information acquisition section 41. Thus, the correction of the vehicle height is performed by removing the vehicle height component resulting from the change in sprung mass velocity from the current vehicle height.

[0092] The vehicle height corrected by the second subtraction section 67 is sent to the second target load calculation section 73.

[0093] The first target load calculation section 71 calculates the first target load relating to the skyhook control on the basis of the first vehicle state quantity (sprung mass velocity) corrected by the first subtraction section 65. Specifically, for example, the first target load calculation section 71 calculates the first target load by multiplying the above-mentioned corrected first vehicle state quantity (sprung mass velocity) by a skyhook attenuation coefficient using a control law based on the skyhook theory.

[0094] The first target load calculated by the first target load calculation section 71 is sent to the merging section 77.

[0095] The second target load calculation section 73 calculates the second target load relating to the preview control on the basis of the vehicle height (actual road surface height) corrected by the second subtraction section 67. Specifically, for example, the second target load calculation section 73 calculates the second target load by multiplying the above-mentioned corrected vehicle height (actual road surface height) by a preview control gain using a control law based on the skyhook theory.

[0096] The second target load calculated by the second target load calculation section 73 is sent to the merging section 77.

[0097] The third target load calculation section 75 calculates the third target load (F R , F L ) on the basis of information relating to the target roll angle θ of the host vehicle 10 calculated by the target roll angle calculation section 69.

[0098] Specifically, the third target load (F R , F L ) relating to the roll generation control for achieving an arbitrary target roll angle θ is calculated on the basis of the information relating to the target roll angle θ of the host vehicle 10 calculated by the target roll angle calculation section 69.R , F L ) can be expressed by the following formula (4).

[0099]

Formula 4

[0100]

[0101] The third target load (F R , F L ) calculated by the third target load calculating section 75 is sent to the merging section 77.

[0102] The merging section 77 performs merging of adding together the first target load calculated by the first target load calculating section 71, the second target load calculated by the second target load calculating section 73, and the third target load calculated by the third target load calculating section 75, and outputs a merged target load.

[0103] The merged target load merged by the merging section 77 is sent to the load control section 45.

[0104] (Action of the electric suspension device 11)

[0105] Next, the action of the electric suspension device 11 of the embodiment of the present application will be described with reference to Figure 6 Figure 6 is a flowchart for explaining the action of the electric suspension device 11 of the embodiment of the present application.

[0106] In Figure 6 , the information acquisition section 41 of the load control ECU 15 acquires various information including the steering angle, the vehicle speed, the preview image, and the vehicle height, the sprung acceleration, and the unsprung acceleration, respectively.

[0107] In step S12, the target roll angle deriving section 61 of the load control ECU 15 derives the target roll angle of the host vehicle 10.

[0108] That is, the lateral acceleration calculating section 68 included in the target roll angle deriving section 61 calculates the lateral acceleration of the host vehicle 10 on the basis of the steering angle and the vehicle speed of the host vehicle 10 acquired by the information acquisition section 41.

[0109] Next, the target roll angle calculating section 69 included in the target roll angle deriving section 61 calculates the target roll angle of the host vehicle 10 on the basis of the lateral acceleration of the host vehicle 10 calculated by the lateral acceleration calculating section 68.

[0110] In step S13, the vehicle state estimating section 63 of the load control ECU 15 estimates the sprung state quantity (first vehicle state quantity: sprung speed) of the present point of time on the basis of the time-series information of the sprung acceleration and the unsprung acceleration acquired by the information acquisition section 41.​

[0111] In step S14, the first subtraction section 65 of the load control ECU 15 subtracts the target roll angle velocity of the host vehicle 10 calculated by the target roll angle calculation section 69 from the current first vehicle state quantity (sprung mass velocity) estimated by the vehicle state estimation section 63. Thus, the correction of the first vehicle state quantity (sprung mass velocity) is performed by removing the roll angle velocity component from the current first vehicle state quantity (sprung mass velocity).

[0112] In step S15, the second subtraction section 67 of the load control ECU 15 subtracts the current second vehicle state quantity (time integral value of sprung mass velocity) estimated by the vehicle state estimation section 63 from the current vehicle height acquired by the information acquisition section 41. Thus, the correction of the vehicle height is performed by removing the vehicle height component due to the change in sprung mass velocity from the current vehicle height.

[0113] In step S16, the target load calculation section 43 of the load control ECU 15 calculates the combined target load.

[0114] That is, the first target load calculation section 71 calculates the first target load related to the skyhook control on the basis of the first vehicle state quantity (sprung mass velocity) corrected by the first subtraction section 65. In the first target load calculation section 71, the first target load for suppressing the vibration (e.g., vibration due to a cause other than the road input) that cannot be coped with by the second target load related to the preview control described below is calculated.

[0115] The second target load calculation section 73 calculates the second target load related to the preview control on the basis of the vehicle height (actual road surface height) corrected by the second subtraction section 67. In the second target load calculation section 73, the second target load for suppressing the vibration due to the road input is calculated.

[0116] The third target load calculation section 75 calculates the third target load on the basis of information related to the target roll angle θ of the host vehicle 10 calculated by the target roll angle calculation section 69. In the third target load calculation section 75, the third target load for generating the target roll angle of the vehicle 10 is calculated.

[0117] The combining section 77 combines the first target load calculated by the first target load calculation section 71, the second target load calculated by the second target load calculation section 73, and the third target load calculated by the third target load calculation section 75, and outputs the combined target load.

[0118] In step S17, the load control section 45 of the load control ECU 15 performs load control of the electromagnetic actuator 13 in compliance with the merged target load that is the result of the operation of step S16. Then, the load control ECU 15 ends the series of processing procedures.

[0119] Effects of the Electric Suspension Device 11 of the Embodiment of the Invention

[0120] The electric suspension device 11 based on the first viewpoint is provided with: an actuator (the electromagnetic actuator 13) that is provided between a vehicle body and a wheel of a vehicle 10, generates a load for damping vibration of the vehicle body; an information acquisition section 41 that acquires information of a sprung state quantity of the vehicle 10 and a running surface state; a target load operation section 43 that calculates a first target load related to skyhook control based on the sprung state quantity, and calculates a second target load related to preview control based on the running surface state; and a load control section 45 that performs load control of the electromagnetic actuator 13 using the operation result of the target load operation section 43.

[0121] The information acquisition section 41 further acquires operation information related to acceleration / deceleration and a steering angle of the vehicle 10, and is further provided with a target roll angle derivation section 61 that derives a target roll angle θ of the vehicle 10 based on the above operation information. As the information related to the acceleration / deceleration and the steering angle of the vehicle 10, it is sufficient to appropriately adopt, for example, information of a vehicle speed, a detection value of an acceleration / deceleration sensor, a steering angle, and the like of the vehicle 10.

[0122] The target load operation section 43 further calculates a third target load related to roll generation control based on the target roll angle θ derived by the target roll angle derivation section 61, and performs operation of a merged target load that merges the first target load and the second target load and the third target load. The load control section 45 performs load control of the electromagnetic actuator 13 using the merged target load.

[0123] In the case where the vehicle 10 in which skyhook control and preview control are installed is moving, the control device originally operates in such a manner as to suppress roll behavior of the vehicle 10 generated in the turning. Thus, when the vehicle 10 is turning in the situation of sporty driving, the driver cannot estimate the tire slip-out timing based on the roll behavior. Therefore, the sense of oneness of the driver with the vehicle in sporty driving is impaired. As a result, there is a concern that the driver feels a sense of incongruity.

[0124] Therefore, in the electric suspension device 11 based on the first viewpoint, the following structure is adopted: the target load calculation section 43 further calculates a third target load related to roll generation control based on the target roll angle θ derived by the target roll angle derivation section 61, and performs calculation of a combined target load that combines the first target load and the second target load and the third target load, and the load control section 45 performs load control of the electromagnetic actuator 13 using the combined target load.

[0125] According to the electric suspension device 11 based on the first viewpoint, calculation of a combined target load that combines a first target load related to skyhook control and a second target load related to preview control and a third target load related to roll generation control is performed, and load control of the electromagnetic actuator 13 is performed using the combined target load, so that comfortable ride feeling with a sense of oneness with the vehicle can be exhibited even when turning is being performed in a sporty driving scenario.

[0126] Further, according to the electric suspension device 11 based on the first viewpoint, in a situation in which a roll behavior occurs in the vehicle 10 as in a situation in which turning is being performed in a sporty driving scenario, roll behavior control of the vehicle is suppressed, so that power consumption can be reduced in correspondence with the suppression of the roll behavior control. As a result, effects related to heat generation protection of the vehicle-mounted battery and long life of the battery can be expected.

[0127] In addition, the electric suspension device 11 based on the second viewpoint can adopt the following structure: in the electric suspension device 11 based on the first viewpoint, a sprung state amount correction section (first subtraction section 65) that corrects a sprung state amount by subtracting a roll angular velocity component based on the target roll angle θ from the above-described sprung state amount (sprung speed) is further provided, and the target load calculation section 43 calculates the first target load related to skyhook control based on the corrected sprung state amount.

[0128] In the electric suspension device 11 based on the second viewpoint, the sprung state amount correction section (first subtraction section 65) corrects the sprung state amount (sprung speed) by subtracting a roll angular velocity component based on the target roll angle θ from the sprung speed, which is the sprung state amount acquired by the information acquisition section 41. In other words, the roll angular velocity component is subtracted from the current sprung speed to correct the sprung state amount (sprung speed). In summary, since the target roll angular velocity component is subtracted from the base data (sprung speed) used to calculate the first target load related to skyhook control, the influence of the target roll angle related to skyhook control can be removed.

[0129] According to the electric suspension device 11 based on the second viewpoint, by subtracting the roll angular velocity component based on the target roll angle θ from the sprung speed as the sprung state quantity, the correction of removing the roll angular velocity component from the current sprung speed is performed with respect to the sprung state quantity (sprung speed), and thus, as compared with the electric suspension device 11 based on the first viewpoint, the conflict of the skyhook control and the roll generation control due to the common roll angular velocity component can be avoided. As a result, the error of the combined target load can be suppressed, and the load control with high precision can be performed.

[0130] In addition, the electric suspension device 11 based on the third viewpoint can adopt a structure in which, in the electric suspension device 11 based on the first viewpoint or the second viewpoint, the derivation of the target roll angle θ in the target roll angle derivation section 61 (see Figure 4 ) is performed using a motion equation of roll action (see Equation 1) that includes a damping coefficient Cs of an imaginary shock absorber 87 (see Figure 5 ) provided between the vehicle body (sprung) and the wheel (unsprung) of the vehicle 10, and the damping coefficient Cs of the imaginary shock absorber 87 is set to an appropriate value corresponding to the user's preference in relation to the roll behavior of the vehicle 10.

[0131] According to the electric suspension device 11 based on the third viewpoint, the derivation of the target roll angle θ in the target roll angle derivation section 61 is performed using a motion equation of roll action that includes a damping coefficient Cs of an imaginary shock absorber 87 provided between the vehicle body (sprung) and the wheel (unsprung) of the vehicle 10, and the damping coefficient Cs of the imaginary shock absorber 87 is set to an appropriate value corresponding to the user's preference in relation to the roll behavior of the vehicle 10, and thus, as compared with the electric suspension device 11 based on the first viewpoint or the second viewpoint, the comfortable ride feeling with further improved sense of oneness with the vehicle can be embodied.

[0132] 〔Other Embodiments〕

[0133] The above-described embodiments show examples of embodiments of the present application. Therefore, the technical scope of the present application is not limited to the embodiments. This is because the present application can be implemented in various ways without departing from the gist or main features thereof.

[0134] For example, in the description of the electric suspension device 11 of the embodiment of the present application, an example in which a total of four electromagnetic actuators 13 are provided on both the front wheels (left front wheel, right front wheel) and the rear wheels (left rear wheel, right rear wheel) is described, but the present application is not limited to this example. A structure in which a total of two electromagnetic actuators 13 are provided on one of the front wheels and the rear wheels can also be adopted.

[0135] Further, in the description of the electric suspension device 11 of the embodiment of the present application, the load control section 45 that independently performs the load control of the plurality of electromagnetic actuators 13 is mentioned. Specifically, the load control section 45 independently performs the load control of the electromagnetic actuators 13 provided for each of the four wheels, respectively, for each wheel.

[0136] However, the load control of the electromagnetic actuators 13 provided for each of the four wheels, respectively, can be independently performed for the front wheel side and the rear wheel side, respectively, or for the left wheel side and the right wheel side, respectively.

[0137] Further, in the description of the electric suspension device 11 of the embodiment of the present application, the example in which the present application is applied to a vehicle that is turning in a sporty driving situation is described, but the present application is not limited to this example. The present application can also be applied to a vehicle that is turning in a normal driving situation.

[0138] Finally, in the description of the electric suspension device 11 of the embodiment of the present application, the ball screw method is described as an example of the drive mechanism of the electromagnetic actuator 13, but the present application is not limited to this example.

[0139] As the drive mechanism of the electromagnetic actuator 13, any drive mechanism such as a linear motor method, a rack and pinion method, a rotary method, or the like can be adopted.

Claims

1. An electric suspension device, comprising: an actuator provided between a vehicle body and a wheel of a vehicle, and generating a load for attenuating a vibration of the vehicle body; an information acquisition unit that acquires information of a sprung state quantity of the vehicle and a running surface state; a target load calculation unit that calculates a first target load related to skyhook control based on the sprung state quantity, and calculates a second target load related to preview control based on the running surface state; and a load control unit that performs load control of the actuator using a calculation result of the target load calculation unit, wherein the electric suspension device is characterized in that: the information acquisition unit further acquires operation information related to an acceleration / deceleration and a steering angle of the vehicle, a target roll angle calculation unit that calculates a target roll angle of the vehicle based on the operation information is further provided, the target load calculation unit further calculates a third target load related to roll generation control based on the target roll angle calculated by the target roll angle calculation unit, and performs calculation of a combined target load that combines the first target load and the second target load and the third target load, and the load control unit performs load control of the actuator using the combined target load, and a sprung state quantity correction unit that corrects the sprung state quantity by subtracting a roll angle velocity component based on the target roll angle from a sprung velocity that is the sprung state quantity is further provided, and the target load calculation unit calculates the first target load related to the skyhook control based on the corrected sprung state quantity.

2. The electric suspension device according to claim 1, wherein the calculation of the target roll angle in the target roll angle calculation unit is performed using a motion equation of roll motion that includes a damping coefficient of an imaginary damper provided between the vehicle body and the wheel of the vehicle, and the damping coefficient of the imaginary damper is set to an appropriate value corresponding to a user's preference related to roll behavior of the vehicle. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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