Suspension control device, vehicle, and suspension control method

Abstract

A technology is provided that can provide a driving feel and ride comfort suitable for a car driver. In the ECU (1), the driving state quantity estimation unit (100) estimates the driving state quantity caused by the operation of the vehicle, the road surface induced state quantity estimation unit (200) estimates the road surface induced state quantity caused by the road surface, and further the driving state quantity conversion unit (300) converts the driving state quantity into the damping force required for driving, the road surface induced state quantity conversion unit (400) converts the road surface induced state quantity into the damping force required for road surface induced, and using these values, the current value calculation unit (500) determines the current value applied to the suspension device, thereby controlling the vehicle's suspension device.

Description

Technical Field

[0001] This invention relates to a suspension control device, a vehicle, and a suspension control method. Background Technology

[0002] In recent years, various dampers have been developed for use in automotive suspensions, featuring variable damping forces that can be controlled stepwise or infinitely. One known mechanism for changing the damping force involves a rotary valve that alters the area of ​​an orifice within a piston. In vehicles equipped with such variable damping force suspensions (hereinafter also referred to as "suspension"), the vehicle's steering stability and ride comfort can be improved by variably controlling the damping force of the damper according to the vehicle's driving conditions.

[0003] Regarding suspension control methods, one method is known for controlling the suspension based on unsprung loads, which are forces input to the vehicle. For example, a method is known in which pitch angular velocity is obtained based on unsprung loads, front and rear accelerations, etc., and control is performed to suppress pitch (see, for example, Patent Document 1).

[0004] Reference List

[0005] Patent documents

[0006] Patent Document 1: WO-A-2014 / 002444 Summary of the Invention

[0007] Technical issues

[0008] Here, fluctuations in the pitch angle of a moving vehicle are generated by upward thrust from the road surface or by acceleration / deceleration operations, and these causes may or may not be predictable to the passenger in advance. The same applies to other state quantities such as rebound velocity and roll angular velocity. However, the inventors have found that even when the state quantities of the actions generated in the vehicle are the same, the driver's ability to predict the actions affects the driver's driving feel and ride comfort. In this specification, actions "caused by the passenger's (driver's) vehicle operation," such as acceleration and deceleration operations and turning operations, can be referred to as "operational guidance." Furthermore, in this specification, actions "caused by the condition of the road surface on which the vehicle travels," such as unevenness and bulges in the road surface, can be referred to as "road surface guidance."

[0009] One aspect of the present invention is to provide a technology that can provide a driving feel and ride comfort suitable for automobile drivers.

[0010] Solution to the problem

[0011] To address the aforementioned problems, a suspension control device according to one aspect of the present invention is a suspension control device for controlling the operation of a vehicle's suspension, comprising: an operation-inducing state quantity estimation unit that estimates an operation-inducing state quantity representing behavior caused by vehicle operation; a road surface-inducing state quantity estimation unit that estimates a road surface-inducing state quantity representing vehicle behavior caused by road surface; an operation-inducing state quantity conversion unit that converts the operation-inducing state quantity into a damping force required for operation-inducing; a road surface-inducing state quantity conversion unit that converts the road surface-inducing state quantity into a damping force required for road surface-inducing; and a current value calculation unit that uses the damping force required for operation-inducing and the damping force required for road surface-inducing to determine a current value to be applied to the suspension.

[0012] Furthermore, in order to solve the above-mentioned problems, a vehicle according to another aspect of the present invention has a suspension controlled by the aforementioned suspension control device.

[0013] Furthermore, to address the aforementioned problems, a suspension control method according to another aspect of the present invention is a suspension control method for controlling the operation of a vehicle's suspension, comprising: an operation-induced state quantity estimation step, estimating an operation-induced state quantity representing behavior caused by vehicle operation; a road-induced state quantity estimation step, estimating a road-induced state quantity representing vehicle behavior caused by road surface; an operation-induced state quantity conversion step, converting the operation-induced state quantity estimated in the operation-induced state quantity estimation step into a damping force required for operation-induced control; a road-induced state quantity conversion step, converting the road-induced state quantity estimated in the road-induced state quantity estimation step into a damping force required for road-induced control; and a current value calculation step, using the damping force required for operation-induced control and the damping force required for road-induced control converted in the operation-induced state quantity conversion step and the road-induced state quantity conversion step to determine a current value to be applied to the suspension.

[0014] Invention Effects

[0015] According to one aspect of the invention, it is possible to provide an operating feel and ride comfort suitable for automobile drivers. Attached Figure Description

[0016] Figure 1 This is a diagram schematically illustrating an example of the construction of a vehicle according to an embodiment of the present invention.

[0017] Figure 2 This is a block diagram illustrating an example of the functional configuration of a suspension control device according to an embodiment of the present invention.

[0018] Figure 3 This is a block diagram illustrating an example of the functional configuration of the operation-induced state quantity estimation unit according to an embodiment of the present invention.

[0019] Figure 4This is a block diagram illustrating an example of the functional configuration of the road surface induced state quantity estimation unit according to an embodiment of the present invention.

[0020] Figure 5 This is a block diagram schematically illustrating the functional configuration of the current value calculation unit according to another embodiment of the present invention.

[0021] Reference tag list

[0022] 1: ECU

[0023] 10: Various sensors

[0024] 11: Wheel speed sensor

[0025] 12: Yaw rate sensor

[0026] 13: Front and rear G sensors

[0027] 14: Lateral G-sensor

[0028] 15: Torque sensor

[0029] 16: Steering angle sensor

[0030] 17: Engine torque sensor

[0031] 18: Engine speed sensor

[0032] 19: Brake pressure sensor

[0033] 20: RAM

[0034] 30: Damping Mapping

[0035] 100: Operation-induced state quantity estimation unit

[0036] 110: Operation of tire travel displacement calculation unit

[0037] 120: Operation-induced state quantity estimation model

[0038] 121, 131, 133, 221, 232: First arithmetic unit; 122, 133, 134, 223, 233: Second arithmetic unit; 123: Input configuration unit.

[0039] 124, 134: Third Arithmetic Unit

[0040] 125, 222, 510: Addition Department

[0041] 126: Fourth Arithmetic Division

[0042] 127, 224: Delay section

[0043] 130: Operation-induced state quantity correction unit

[0044] 132, 231: Subtraction section

[0045] 140: Operation-induced state quantity correction addition section

[0046] 200: Road Path Induction State Estimation Department

[0047] 210: Road surface tire travel displacement calculation unit

[0048] 220: Road Path Induction State Estimation Model

[0049] 230: Road surface induced state quantity correction unit

[0050] 240: Additive part of road traction state quantity correction

[0051] 300: Operation-induced state quantity conversion unit

[0052] 400: Road surface induced state quantity conversion unit

[0053] 500, 600: Current value calculation section

[0054] 520: Required Current Mapping

[0055] 530: Operation-induced required current mapping

[0056] 540: Required Current Mapping for Road Surface Induction

[0057] 900: Vehicles

[0058] 910: Body

[0059] 920, 920A, 920B, 920C, 920D: Wheels

[0060] 921, 921A, 921B, 921C, 921D: Tires

[0061] 930: Suspension system

[0062] 941: Rack and pinion shaft

[0063] 942: Rack and pinion mechanism

[0064] 943: Torque application section

[0065] 944: Steering Axle

[0066] 945: Steering components

[0067] 950: Engine

[0068] 970: Power generation unit

[0069] 980: Battery Detailed Implementation

[0070] The inventors have discovered that even when the state quantities of behaviors generated in a vehicle are the same, the driving feel and ride comfort are affected by whether the driver can predict the behaviors. This invention is based on the above-mentioned findings and provides a technique capable of providing a driving feel and riding comfort suitable for automobile drivers. Embodiments of the invention will be described in more detail below.

[0071] [First Embodiment]

[0072] [vehicle]

[0073] The vehicle according to an embodiment of the present invention has a suspension. The suspension is configured to be controlled by a suspension control device. Figure 1 This is a diagram that schematically illustrates an example of a vehicle configuration according to an embodiment of the present invention.

[0074] like Figure 1 As shown, vehicle 900 includes a suspension system (suspension) 930, body 910, wheels 920, tires 921, steering components 945, steering shaft 944, torque sensor 15, steering angle sensor 16, torque application unit 943, rack and pinion mechanism 942, rack shaft 941, engine 950, electronic control unit (ECU) 1, power generation unit 970, and battery 980. Examples of vehicle 900 include gasoline vehicles, hybrid electric vehicles (HEV vehicles), and electric vehicles (EV vehicles).

[0075] Wheels 920, fitted with tires 921, are suspended from the body 910 via suspension devices 930. Since the vehicle 900 is a four-wheeled vehicle, it is equipped with four suspension devices 930, four wheels 920, and four tires 921. 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 921A and wheel 920A, tire 921B and wheel 920B, tire 921C and wheel 920C, and tire 921D and wheel 920D, respectively. Similarly, in the following text, the configurations attached to the left front wheel, right front wheel, left rear wheel, and right rear wheel can be indicated by adding the reference letters "A", "B", "C", and "D".

[0076] [Suspension system (suspension)]

[0077] The suspension device 930 includes a hydraulic shock absorber, an upper arm, and a lower arm. Further, as an example, the hydraulic shock absorber includes a solenoid valve, which is a solenoid valve for adjusting the damping force generated by the hydraulic shock absorber. However, this does not limit this embodiment, and the hydraulic shock absorber can use a solenoid valve other than a solenoid valve as the solenoid valve for adjusting the damping force. For example, a solenoid valve using an electromagnetic fluid (magnetofluid) can be configured as described above.

[0078] [Steering mechanism]

[0079] A steering component 945 operated by the driver is connected to one end of a steering shaft 944 to transmit torque, and the other end of the steering shaft 944 is connected to a rack and pinion mechanism 942.

[0080] In the above description, "connected in order to transmit torque" means that components are connected such that rotation of one component causes rotation of another component. For example, this includes at least the following cases: one component is integrally molded with another component; one component is directly or indirectly fixed to another component; and one component and another component are connected in a way that interlocks with each other via a joint component or the like.

[0081] The rack and pinion mechanism 942 is a mechanism for converting the rotation of the steering shaft 944 about its axis into displacement along the axis of the rack shaft 941. When the rack shaft 941 is displaced in the axial direction, the wheels 920A and 920B are steered via the tie rod and the steering knuckle arm.

[0082] Torque sensor 15 detects the steering torque applied to steering shaft 944, in other words, the steering torque applied to steering component 945, and provides a torque sensor signal indicating the detection result to ECU 1. More specifically, torque sensor 15 detects the torsion of a torsion bar built into steering shaft 944 and outputs the detection result as a torque sensor signal. A magnetostrictive torque sensor can be used as torque sensor 15.

[0083] Steering angle sensor 16 detects the steering angle of steering component 945 and provides the detection result to ECU1.

[0084] The torque application unit 943 applies auxiliary torque or counter torque according to the steering control quantity supplied from the ECU 1 to the steering shaft 944. The torque application unit 943 includes: a motor that generates auxiliary torque or counter torque according to the steering control quantity; and a torque transmission mechanism that transmits the torque generated by the motor to the steering shaft 944.

[0085] Specific examples of "control quantities" in this manual include current value, duty cycle, attenuation rate, and attenuation ratio.

[0086] Furthermore, in the above example, a steering device in which the steering component 945 is always mechanically connected to the rack shaft 941 is used as an example, but this embodiment is not limited to this. The steering device according to this embodiment can be, for example, a steering device of the steer-by-wire type. The matters described below in this specification can also be applied to steering devices of the steer-by-wire type.

[0087] [Drive force transmission device]

[0088] Vehicle 900 has a drive force transmission device (not shown). This drive force transmission device, for example, is a device that transmits engine power to the front or rear wheels and has a gear transmission mechanism. The gear transmission mechanism is a differential device that imparts a difference in the rotational speed of each wheel in the front or rear wheels as needed, and this gear transmission mechanism has a differential limiting device that limits the differential based on the driving conditions of vehicle 900. In this embodiment, the differential device and the differential limiting device are not limited. The differential device can be, for example, a bevel gear type differential device, and the differential limiting device can be a torque-sensitive device, such as a multi-plate clutch type limited-slip differential (LSD) or a helical gear type LSD, or it can be a rotational differential-sensitive device, such as a viscous LSD.

[0089] [Other Configurations]

[0090] The generator 970 is attached to the engine 950, and the power generated by the generator 970 is stored in the battery 980.

[0091] In addition, the vehicle 900 includes wheel speed sensors 11 configured for each wheel 920 and detecting the wheel speed (angular velocity ω) of each wheel 920. Furthermore, the vehicle 900 may be configured to include: a lateral G-sensor 14 for detecting the lateral acceleration of the vehicle 900; a front and rear G-sensor 13 for detecting the longitudinal acceleration of the vehicle 900; a yaw rate sensor 12 for detecting the yaw rate of the vehicle 900; an engine torque sensor 17 for detecting the torque generated by the engine 950; an engine rotation speed sensor 18 for detecting the rotational speed of the engine 950; and a brake pressure sensor 19 for detecting the pressure of the brake fluid applied to the braking system. The detection results of these various sensors are provided to the ECU 1.

[0092] Although not shown, vehicle 900 includes: an anti-lock braking system (ABS) that prevents wheel lock-up during braking; a traction control system (TCS) that suppresses wheel slippage during acceleration, etc.; and a vehicle stability assist (VSA) controllable braking device, which is a vehicle behavior stability control system equipped with automatic braking function and braking assist function for yaw moment control during cornering.

[0093] Here, ABS, TCS, and VSA compare the wheel speed determined based on the estimated vehicle speed with the wheel speed detected by wheel speed sensor 11. Then, ABS, TCS, and VSA determine that the vehicle is in a slipping state when the difference between these two wheel speed values ​​exceeds a predetermined value. Through this process, ABS, TCS, and VSA aim to stabilize the behavior of vehicle 900 by performing optimal braking control or traction control based on the driving state of vehicle 900.

[0094] Furthermore, the provision of detection results from the aforementioned sensors to ECU 1 and the transmission of control signals from ECU 1 to each component are performed via Controller Area Network (CAN) 2.

[0095] In addition, vehicle 900 has random access memory (RAM) (not shown). RAM stores steady-state or estimated values, such as vehicle weight, inertial load, and vehicle specifications, as well as calculated values. Steady-state values ​​are, for example, values ​​of physical quantities specific to vehicle 900.

[0096] Furthermore, vehicle 900 includes an ECU (not shown) for controlling the operation of the suspension system 930, steering system, and drive force transmission device. For example, vehicle 900 has a damper ECU for controlling the suspension system 930. Such an ECU dedicated to the vehicle 900 can be located in the device to be controlled, or it can be located in ECU 1 for controlling vehicle 900. As described above, the suspension system 930, steering system, and drive force transmission device in vehicle 900 are all configured to be electronically controllable, and can also be described as electronically controlled suspension, electronically controlled steering, and electronically controlled drive force transmission device.

[0097] [Overview of Suspension Control]

[0098] ECU 1 controls the suspension assembly 930 by providing suspension control parameters. More specifically, ECU 1 controls the opening and closing of the solenoid valve by supplying suspension control parameters to the solenoid valve included in the hydraulic shock absorber in the suspension assembly 930. To achieve this control, power lines are arranged for supplying drive power from ECU 1 to the solenoid valve.

[0099] [Steering Control Overview]

[0100] Furthermore, the ECU 1 comprehensively controls various electronic devices included in the vehicle 900. More specifically, the ECU 1 controls the magnitude of the auxiliary torque or reaction torque applied to the steering shaft 944 by adjusting the steering control amount supplied to the torque application unit 943.

[0101] [Overview of Drive Force Transmission Device Control]

[0102] ECU 1 controls the drive force transmission device by supplying control quantities such as differential limiting. To give a concrete example, by adjusting the clutch engagement strength in a multi-plate clutch-type LSD according to driving conditions, ECU 1 distributes the engine's drive force between the front and rear wheels, or between the left and right wheels on the front or rear wheels, and controls the individual rotational speed of the wheels rotated by the engine's drive force.

[0103] [Functional Configuration of Suspension Control System]

[0104] ECU 1 includes suspension control devices. Figure 2 This is a block diagram illustrating an example of the functional configuration of a suspension control device according to an embodiment of the present invention. Figure 2 As shown, the suspension control device includes an operation guidance state quantity estimation unit 100, a road surface guidance state quantity estimation unit 200, an operation guidance state quantity conversion unit 300, a road surface guidance state quantity conversion unit 400, and a current value calculation unit 500. The suspension control device controls the operation of the vehicle suspension.

[0105] [Estimation of operation-induced state quantities]

[0106] The operation-induced state quantity estimation unit 100 estimates operation-induced state quantities representing the behavior caused by vehicle operation. For example, the operation-induced state quantity estimation unit 100 estimates the state quantities of vehicle behavior by referring to the force applied to the tires and the change in tire size caused by the driver's vehicle operation. Furthermore, the operation-induced state quantity estimation unit 100 estimates the state quantities of vehicle behavior caused by the driver's vehicle operation by using a Kalman filter. Figure 3 This is a block diagram illustrating an example of the functional configuration of the operation-induced state quantity estimation unit according to an embodiment of the present invention.

[0107] like Figure 2 As shown, the operation-induced state quantity estimation unit 100 includes an operation tire stroke displacement calculation unit 110, an operation-induced state quantity estimation model 120, an operation-induced state quantity correction unit 130, and an operation-induced state quantity correction addition unit 140.

[0108] The tire travel displacement calculation unit 110 calculates the tire travel displacement TireST caused by the driver's operation. inertia The tire travel displacement is the amount of tire deformation (displacement) caused by a load applied to the tire due to the driver's vehicle operation, and is expressed in units of length. As an example of a calculation method, there is a method that calculates the inertial load of each wheel as a load fluctuation caused by the driver's vehicle operation, and multiplies this inertial load by a converted value G representing the tire's elastic constant. As a method for calculating the inertial load, for example, the method described in Japanese Patent No. 6748765 can be used.

[0109] Operation-induced state quantity estimation model 120 estimates the vehicle's state quantities (operation-induced state quantities) caused by driver operations. For example... Figure 3 As shown, the operation-induced state quantity estimation model 120 includes a first arithmetic unit 121, a second arithmetic unit 122, an input quantity configuration unit 123, and an input matrix B. inertia 124. Addition part; 125. System matrix A inertia 126 and delay part 127.

[0110] The operational induced state quantity estimation model 120 obtains the values ​​G of the front and rear acceleration sensors as front and rear accelerations from various sensors 10. x and the value G of the lateral acceleration sensor as lateral acceleration. y The longitudinal acceleration is the acceleration of the vehicle in the longitudinal direction, and the lateral acceleration is the acceleration of the vehicle in the lateral direction. Furthermore, the operation-induced state quantity estimation model 120 obtains the vehicle weight m from RAM 20. Additionally, the operation-induced state quantity estimation model 120 obtains the damping force DampF.

[0111] In this embodiment, the operation-induced state quantity estimation model 120 obtains the applied current I and damper speed DampV from RAM 20, and obtains the damping force DampF from the damping map 30, which is a mapping for outputting the damping force DampF. The applied current I is the value of the current applied to the solenoid valve used to control the damping force in the suspension damper. For example, the applied current I and damper speed DampV are fed back from the damper ECU into RAM 20, and the damping map 30 is able to acquire this data.

[0112] The first arithmetic unit 121 processes the values ​​G from the front-rear acceleration sensors obtained from various sensors 10. x Multiply by the vehicle weight m obtained from RAM 20 to obtain the total front and rear tire forces F. x0 The second arithmetic unit 122 processes the value G of the lateral acceleration sensor acquired from various sensors 10. y Multiply by the vehicle weight m obtained from RAM 20 to obtain the total tire lateral force F. y0 .

[0113] Input configuration unit 123 obtains the total front and rear tire forces F. x0 Total tire lateral force F y0 And the damping force DampF, and obtain the input quantity. The input quantity can be represented by a matrix.

[0114] The induced state quantity estimation model 120 obtains the above input quantities, and multiplies these input quantities by the input matrix B. inertia 124, and calculate the input quantity and input matrix B. inertia The product of 124 causes the operation-induced state quantity estimation model 120 to calculate a first operation-induced state quantity, which is a state quantity caused by the driver's operation in the vehicle under the control.

[0115] The addition unit 125 adds the first operation-induced state quantity and the "value based on the previous estimation result" to obtain the second operation-induced state quantity caused by the driver's operation in the vehicle.

[0116] In this embodiment, the operation-induced state quantity estimation model 120 is a state-space model. Therefore, in the operation-induced state quantity estimation model 120, the input is obtained by multiplying the feedback of the "previous estimation result" by the system matrix A. inertia The value obtained by adding the operation-induced state quantity (OID) is 126. This value is input to the addition unit 125 as a "value based on the previous estimation result". The addition result is the output value of the operation-induced state quantity estimation model 120, that is, the estimation result. In this embodiment, the "previous estimation result" of the operation-induced state quantity estimation model 120 is obtained by adding the operation-induced state quantity StateQ via the delay unit 127. inertia The value obtained is the state variable StateQ induced by this operation. inertia It is calculated by the operation-induced state quantity correction adder 140, which will be described below.

[0117] Assuming the current number of operations is n, the delay unit 127 has an operation-induced state variable StateQ that will be used at time n-1. inertia The functions supplied to each of the operation-induced state quantity estimation model 120 and the operation-induced state quantity correction unit 130.

[0118] The operation-induced state quantity correction unit 130 calculates the correction amount for the operation-induced state quantity. The operation-induced state quantity correction unit 130 includes an operation-induced state quantity correction observation construction unit 131, a subtraction unit 132, and a system matrix C. inertia 133 and Kalman gain K inertia 134.

[0119] The operation-induced state quantity correction observation construction unit 131 acquires the yaw rate sensor value r from each sensor 10, and acquires the operation tire travel displacement TireST of each wheel of the vehicle from the operation tire travel displacement calculation unit 110. inertia Then, a correction observation for the operation-induced state variables is constructed. This correction observation is a 5×1 matrix that includes the current changes in tire displacement. In other words, tire travel displacement is the change in tire radius, which is one aspect of tire variation.

[0120] The subtraction unit 132 acquires the above-mentioned operation-induced state quantity correction observation and subtracts the "value based on the previous estimation result" from the operation-induced state quantity correction observation, so that each element of the operation-induced state quantity correction observation becomes the change from the value based on the "previous estimation result".

[0121] In subtraction section 132, the input is obtained by multiplying the "previous estimate" by the observation matrix C. inertiaThe value obtained by 133 (e.g., a p×5 matrix). This value is the "value based on previous estimates" mentioned above. In this way, the previous estimates are used as a measure of the observed matrix C. inertia Feedback from 133 is input to the subtraction unit 132. In this embodiment, the "previous estimate result" of the operation-induced state quantity correction unit 130 is the same as the "previous estimate result" of the operation-induced state quantity estimation model 120.

[0122] The operation-induced state quantity correction unit 130 multiplies the calculation result of the subtraction unit 132 by the Kalman gain K. inertia 134. Kalman gain K inertia 134 is the gain of the Kalman filter. In this way, the operation-induced state quantity correction unit 130 calculates the output value. The output value of the operation-induced state quantity correction unit 130 is the correction amount for the operation-induced state quantity.

[0123] As described above, in this embodiment, the operation-induced state quantity estimation model 120 corresponds to the estimation model section of the Kalman filter, and the operation-induced state quantity correction section 130 corresponds to the filtering section of the Kalman filter. In this embodiment, the Kalman gain K in the operation-induced state quantity correction section 130... inertia 134 is time-invariant, but it can be time-varying.

[0124] The output values ​​of the operation-induced state quantity estimation model 120 and the operation-induced state quantity correction unit 130 are input into the operation-induced state quantity correction adder 140. Then, the operation-induced state quantity StateQ is calculated. inertia As the output value of the operation-induced state quantity correction adder 140, this output value is the sum of these values. Operation-induced state quantity StateQ inertia The corrected estimation result is obtained by correcting the estimation result of the operation-induced state quantity estimation model 120 using a Kalman filter.

[0125] [Estimation of pavement induced state quantities]

[0126] The road surface induced state quantity estimation unit 200 estimates road surface induced state quantities that represent vehicle behavior caused by the road surface. For example, the road surface induced state quantity estimation unit 200 estimates the state quantities of vehicle behavior by referring to the forces applied to the tires caused by the road surface and the changes in tire size. Further, in this embodiment, the road surface induced state quantity estimation unit 200 estimates the state quantities of vehicle behavior caused by the road surface input using a Kalman filter. In the following description, some explanations will be omitted for parts common to the operation induced state quantity estimation model 120.

[0127] like Figure 2As shown, the road surface induced state quantity estimation unit 200 includes a road surface tire travel displacement calculation unit 210, a road surface induced state quantity estimation model 220, a road surface induced state quantity correction unit 230, and a road surface induced state quantity correction addition unit 240.

[0128] Road surface tire travel displacement calculation unit 210 calculates road surface tire travel displacement (TireST). road Road tire travel displacement is the amount of tire deformation (displacement) caused by the load applied to the tire due to road input, and is expressed in units of length. Road tire travel displacement can be calculated, for example, by calculating the road load on each wheel of the vehicle as a load fluctuation caused by road input, and multiplying that road load by a converted value G representing the tire's elastic constant. As a method for calculating the road load, for example, the method described in Japanese Patent No. 6695481 can be used.

[0129] Figure 4 This is a block diagram illustrating an example of the functional configuration of the road surface induced state quantity estimation unit according to an embodiment of the present invention. The road surface induced state quantity estimation model 220 estimates the vehicle state quantities (road surface induced state quantities) caused by road surface input. Figure 4 As shown, the pavement induced state quantity estimation model 220 can be constructed with the same functional configuration as the operation induced state quantity estimation model 120. The pavement induced state quantity estimation model 220 includes an input matrix B. road 221. Addition part; 222. System matrix A road 223 and delay part 224.

[0130] The road surface induced state quantity estimation model 220 obtains the damping force DampF from the damping mapping 30.

[0131] The pavement induced state quantity estimation model 220 obtains the damping force DampF and multiplies the damping force DampF by the input matrix B. road 221 Calculate a first road surface induced state quantity, which is the state quantity of the vehicle caused by the road surface input in the vehicle under the control.

[0132] The addition unit 222 adds the first road surface guidance state quantity and the "value based on the previous estimation result" to obtain the second road surface guidance state quantity caused by the driver's operation in the vehicle.

[0133] In this embodiment, the pavement induced state quantity estimation model 220 consists of a state-space model. Therefore, in the pavement induced state quantity estimation model 220, the input is obtained by multiplying the feedback of the previous estimation result by the system matrix A. roadThe value obtained by 223 is input to the addition unit 222 as a "value based on the previous estimation result". The summation result is the output value of the pavement induced state quantity estimation model 220, i.e., the estimation result. In this embodiment, the "previous estimation result" of the pavement induced state quantity estimation model 220 is obtained from the pavement induced state quantity StateQ. road The obtained value is the road induced state variable StateQ. road The road surface induced state quantity correction addition unit 240, which will be described later, is calculated via the delay unit 224.

[0134] Assuming the current number of operations is n, then the delay unit 224 has the road surface induced state variable StateQ at time n-1. road Provides functionality to each of the pavement induced state quantity estimation model 220 and the pavement induced state quantity correction unit 230.

[0135] The pavement guidance state quantity correction unit 230 calculates the correction amount of the pavement guidance state quantity. The pavement guidance state quantity correction unit 230 can be configured to have the same functional configuration as the operational guidance state quantity correction unit 130. The pavement guidance state quantity correction unit 230 includes a subtraction unit 231 and an observation matrix C. road 232 and Kalman gain K road 233.

[0136] Subtraction unit 231 obtains the road tire travel displacement (TireST) of each wheel of the vehicle from road tire travel displacement calculation unit 210. road The road surface tire travel displacement (TireST) of each wheel of the vehicle obtained by subtraction unit 231 is then calculated. road The result is a 4×1 matrix. The matrix includes the current tire change and the operational induced state quantity correction observation, and becomes the road induced state quantity correction observation. The subtraction unit 231 subtracts the "value based on the previous estimate" from the road induced state quantity correction observation, such that each element of the road induced state quantity correction observation becomes the change from the value based on the "previous estimate".

[0137] In the subtraction section 231, the input is obtained by multiplying the "previous estimate" by the observation matrix C. road The value obtained is 232. This value is the aforementioned "value based on previous estimates". In this way, the previous estimates are used as a reference to the observation matrix C. road Feedback from 232 is input to subtraction unit 231. In this embodiment, the "previous estimate" of pavement induced state quantity estimation model 220 is the same as the "previous estimate" of pavement induced state quantity estimation model 220.

[0138] The road induced state quantity correction unit 230 multiplies the calculation result of the subtraction unit 231 by the Kalman gain K. road233. Kalman gain K road 233 is the gain of the Kalman filter. The output value of the pavement induced state quantity correction unit 230 is calculated in this manner. The output value of the pavement induced state quantity correction unit 230 is the correction amount for the pavement induced state quantity.

[0139] As described above, in this embodiment, the pavement induced state quantity estimation model 220 corresponds to the estimation model section of the Kalman filter, and the pavement induced state quantity correction section 230 corresponds to the filtering section of the Kalman filter. The Kalman gain K in the pavement induced state quantity correction section 230... road 233 is also time-invariant in this embodiment, but it can be time-varying.

[0140] The output values ​​of the pavement induced state quantity estimation model 220 and the pavement induced state quantity correction unit 230 are input into the pavement induced state quantity correction adder 240. Then, the pavement induced state quantity StateQ is calculated. road As the output value of the pavement induced state quantity correction adder 240, this output value is the sum of these values. Pavement induced state quantity StateQ road This is the corrected estimation result, where the estimation result of the road induced state quantity estimation model 220 is corrected by the above Kalman filter.

[0141] [Transition of Operation-Induced State Variables]

[0142] The operation-induced state quantity conversion unit 300 converts the operation-induced state quantity estimated by the operation-induced state quantity estimation unit into the damping force required for operation induction. For example, the operation-induced state quantity conversion unit 300 will convert the operation-induced state quantity StateQ calculated in the operation-induced state quantity correction addition unit 140 into the damping force required for operation induction. inertia Converted to the damping force required for operation induction (DampRQST) inertia Damping force required for operation induction (DampRQST) inertia This refers to the required damping force needed to control changes in vehicle behavior caused by operation. The operation-induced state quantity conversion unit 300 converts the operation-induced state quantity StateQ... inertia Multiply by a predetermined coefficient to generate the operation-induced state variable StateQ. inertia Converted to the damping force required for operation induction (DampRQST) inertia .

[0143] [Transformation of pavement induced state quantities]

[0144] The pavement induced state quantity conversion unit 400 converts the pavement induced state quantity estimated by the pavement induced state quantity estimation unit into the damping force required for pavement induced state. For example, the pavement induced state quantity conversion unit 400 converts the pavement induced state quantity StateQ into the required damping force for pavement induced state. roadConverted to the required damping force DampRQST for road surface induction road Damping force required for road surface induction (DampRQST) road This refers to the damping force required to control changes in vehicle behavior caused by the road surface. The road surface induced state quantity conversion unit 400 converts the road surface induced state quantity StateQ... road Multiply by a predetermined coefficient to obtain the road induced state variable StateQ. road Converted to the required damping force DampRQST for road surface induction road .

[0145] [State transitions when state variables are identical]

[0146] Here, in this embodiment, when the induced state variable StateQ is operated... inertia With the road surface induced state quantity StateQ road At the same time, the pavement induced state quantity conversion unit 400 converts the pavement induced state quantity StateQ road Converted to the required damping force DampRQST for road surface induction road To achieve the required damping force DampRQST for road surface induction road Damping force required for operation induction (DampRQST) inertia Different. More specifically, in this embodiment, the road surface induction state quantity conversion unit 400 makes the damping force DampRQST required for road surface induction different. road Unlike the damping force required for operation induction, DampRQST inertia This results in the required damping force DampRQST for road surface induction. road The damping force becomes less than the required damping force for operation induction (DampRQST). inertia .

[0147] "When the operation induces the state variable StateQ" inertia and the state quantity StateQ induced by the road surface road "Same" can mean that these state quantities are completely identical, or that they are substantially the same. For example, "substantially the same" means that some components of two state quantities are identical, or that some or all of the components of each state quantity are different only to the extent that the quantities are substantially the same.

[0148] In this embodiment, even when the operation induces the state variable StateQ inertia With the road surface induced state quantity StateQ road When some or all of the shared state quantities are the same, in ECU1, the operation-inducing state quantity conversion unit 300 also generates the damping force DampRQST required for operation induction. inertiaFurthermore, the road surface induction state quantity conversion unit 400 also generates the damping force DampRQST required for road surface induction. road This makes the damping force required for operation induction DampRQST inertia Relatively smaller than the damping force required for road surface induction (DampRQST) road For example, even when the operation induces the state variable StateQ inertia and the road surface induced state quantity StateQ road When some or all of the shared state variables are the same, the operation-induced state variable transition unit 300 will also convert the operation-induced state variable StateQ. inertia Converted to the damping force required for operation induction (DampRQST) inertia Therefore, the road induced state quantity StateQ is converted by the road induced state quantity conversion unit 400. road Converted to the required damping force DampRQST for road surface induction road The situation is small.

[0149] To create a relative difference between the two quantities, for example, this can be achieved by converting both state quantities into the desired damping force of the same magnitude at once, and then passing each converted damping force through a gain with a different gain width in each damping force. The comparison of each converted damping force and the determination of the gain can be performed by any functional configuration in ECU 1. Furthermore, each gain can have an appropriate magnitude to achieve a balance between handling feel and ride comfort, which will be described below, and each gain can be appropriately determined based on experimental or computer simulation results.

[0150] With this configuration, this embodiment enables, for example, damping force control that emphasizes handling feel, and also allows for a wide range of settings within the control. Therefore, both handling feel and ride comfort can be achieved within the range desired by the vehicle driver.

[0151] For example, suppose the driver wants to emphasize ride comfort. Preferably, the damping force is controlled to suppress roll (road-induced state quantity StateQ) caused by road conditions that cannot be predicted by the passenger. road The component of the road surface bump is used to reduce the feeling of upward thrust or to transmit road bumps to passengers. On the other hand, when the passenger can predict the roll caused by the operation (operation-induced state quantity StateQ) inertia When the damping force is suppressed too much, the sense of operation is diluted, and there is a concern that phenomena such as motion sickness may occur. Therefore, it is preferable to control the damping force to suppress the cause of operation to a degree that allows the passenger to have a proper sense of operation.

[0152] In this embodiment, for example, the gain width of the gain provided by the operation-inducing state quantity conversion unit 300 is set to a value relatively smaller than the gain width of the gain provided by the road surface-inducing state quantity conversion unit 400. This allows for the control of the damping force transmitting an appropriate operation feel while mitigating the sensation of upward thrust or road bumps to the passenger, further achieving both operation feel and ride comfort. In this embodiment, from the viewpoint of obtaining the same advantages, the gain width of the gain provided by the road surface-inducing state quantity conversion unit 400 can be set to a value relatively larger than the gain width of the gain provided by the operation-inducing state quantity conversion unit 300.

[0153] [Determine the current value to be applied to the suspension]

[0154] The current calculation unit 500 uses the damping force required for operation induction converted by the operation induction state quantity conversion unit and the damping force required for road induction converted by the road induction state quantity conversion unit to determine the current value to be applied to the suspension. The current calculation unit 500 includes an adder 510 and a required current mapping 520.

[0155] Addition unit 510 induces the required damping force DampRQST through operation. inertia Damping force required for road surface induction (DampRQST) road The required damping force DampRQST is calculated by adding them together.

[0156] The required current mapping 520 is an example of a current value calculation unit. The required current mapping 520 obtains the required damping force DampRQST from the adder 510, and also obtains the damper speed DampV. The damper speed DampV can be obtained, for example, through feedback from the damper ECU or a stroke sensor. In this embodiment, the required current mapping 520 obtains the damper speed DampV from RAM 20 in the same manner as the damping mapping 30. The required current mapping 520 determines the current value to be applied to the solenoid valve to control the damping force based on the required damping force DampRQST and the damper speed DampV. At the determined current value, power is supplied to the solenoid valve, and the suspension corresponding to each wheel of the vehicle is controlled.

[0157] [Overview of this embodiment]

[0158] As clearly shown in the above description, the suspension control device (ECU 1) of the first embodiment of the present invention is a suspension control device that controls the operation of the suspension (suspension device 930) of a vehicle (900). The suspension control device includes: an operation-induced state quantity estimation unit (100) that estimates an operation-induced state quantity (StateQ) representing the behavior caused by the operation of the vehicle. inertia); Road surface induced state quantity estimation unit (200), which estimates the road surface induced state quantity (StateQ) representing the behavior of vehicles caused by the road surface. road The operation-induced state quantity conversion unit (300) converts the operation-induced state quantity into the damping force DampRQST required for operation induction. inertia The pavement induction state quantity conversion unit (400) converts the pavement induction state quantity into the damping force DampRQST required for pavement induction. road ; and a current value calculation unit (500) that uses the damping force required for operation induction and the damping force required for road surface induction to determine the current value to be applied to the suspension.

[0159] Furthermore, the vehicle according to the first embodiment of the present invention has a suspension controlled by the aforementioned suspension control device.

[0160] Furthermore, the suspension control method of the first embodiment of the present invention is a suspension control method for controlling the operation of a vehicle suspension. The suspension control method includes: an operation-induced state quantity estimation step, estimating an operation-induced state quantity representing behavior caused by vehicle operation; a road-induced state quantity estimation step, estimating a road-induced state quantity representing vehicle behavior caused by the road surface; an operation-induced state quantity conversion step, after the operation-induced state quantity estimation step, converting the operation-induced state quantity into a damping force required for operation-induced behavior; a road-induced state quantity conversion step, after the road-induced state quantity estimation step, returning the road-induced state quantity to a damping force required for road-induced behavior; and a current value calculation step, after the operation-induced state quantity conversion step and the road-induced state quantity conversion step, using the damping force required for operation-induced behavior and the damping force required for road-induced behavior to determine a current value to be applied to the suspension.

[0161] Therefore, the first embodiment of the present invention can provide an operating feel and ride comfort suitable for automobile drivers.

[0162] In this embodiment, when the handling guidance state quantity and the road surface guidance state quantity are the same, the road surface guidance state quantity conversion unit converts the road surface guidance state quantity into the damping force required for road surface guidance, so that the damping force required for handling guidance is different from the damping force required for road surface guidance. From the viewpoint of providing a favorable balance between providing the driver with handling feel and ride comfort, this configuration is even more effective.

[0163] In this embodiment, by converting the road surface induced state quantity into the damping force required for road surface induced state, the damping force required for road surface induced state is made relatively smaller than the damping force required for maneuver induced state. The road surface induced state quantity conversion unit makes the damping force required for road surface induced state different from the damping force required for maneuver induced state. This configuration is even more effective from the perspective of vehicle control in the preferred state where the driver has both a sense of operation and ride comfort.

[0164] [Second Embodiment]

[0165] Another embodiment of the present invention will now be described. For ease of description, the same reference numerals will be given to components having the same function as those described in the above embodiments, and their descriptions will not be repeated.

[0166] In this embodiment, the tire travel displacement calculation unit 110 treats the ground contact load described in patent document JP-A2013-216278 as an inertial load and calculates TireST. inertia Furthermore, the road surface tire travel displacement calculation unit 210 treats the unsprung load described in International Publication No. 2014 / 002444 as the road surface load and calculates TireST. road As described above, the present invention can be implemented using a variety of methods, and in any case, it should be construed as being included in the claims of this application.

[0167] In this embodiment, when the operation-induced state quantity and the road surface-induced state quantity are the same, the road surface-induced state quantity conversion unit converts the road surface-induced state quantity into the road surface-induced damping force by making the damping force required for road surface-induced damping different from the damping force required for operation-induced damping, so that the damping force required for road surface-induced damping is greater than the damping force required for operation-induced damping. Otherwise, this embodiment is the same as the first embodiment described above.

[0168] In this embodiment, even when the operation induces the state variable StateQ inertia and the road surface induced state quantity StateQ road When some or all of the shared state variables are the same, ECU1 will also cause the operation induction state variable conversion unit 300 to acquire the damping force DampRQST required for operation induction. inertia And enable the pavement induced state quantity conversion unit 400 to obtain the damping force DampRQST required for pavement induction. road This makes the damping force required for operation induction DampRQST inertia The damping force required for road surface induction is relatively greater than DampRQST. road For example, even when the operation induces the state variable StateQ inertia and the road surface induced state quantity StateQ roadWhen some or all of the shared state variables are the same, the operation-induced state variable transition unit 300 will also convert the operation-induced state variable StateQ. inertial Converted to the damping force required for operation induction (DampRQST) inertia This causes the road induced state quantity conversion unit 400 to convert the road induced state quantity StateQ to a value greater than that of the road induced state quantity conversion unit. road Converted to the required damping force DampRQST for road surface induction road Similar to the first embodiment described above, the relative difference in magnitude between the two desired damping forces can be achieved, for example, by converting the two state variables into desired damping forces of the same magnitude, and then making each converted damping force have a gain with a different gain width in each damping force.

[0169] Here, we assume a situation where information transmission from the road surface, such as when driving on uneven roads, should be given greater importance. In this case, the gain width provided in the road-induced state quantity conversion unit 400 is set to not suppress the road-induced state quantity StateQ so much. road The value of . Furthermore, in order to make the road induced state variable StateQ road More obviously, setting the gain width of the gain provided in the operation guidance state quantity conversion unit 300 to a value that transmits the impact of vehicle movement caused by driving actions to the passenger is smaller than emphasizing ride comfort. For example, the gain width of the gain provided in the operation guidance state quantity conversion unit 300 is set to a value that is relatively larger than the gain width of the gain provided in the road surface guidance state quantity conversion unit 400. Therefore, as described above, it is possible to highlight and transmit as much information from the road surface as possible to the passenger.

[0170] In this embodiment, the road surface induced state quantity is converted into the damping force required for road surface induced state, making the damping force required for road surface induced state relatively greater than the damping force required for maneuvering induced state. The road surface induced state quantity conversion unit makes the damping force required for road surface induced state different from the damping force required for maneuvering induced state. Given the emphasis on the transmission of information from the road surface, this configuration is even more effective from the viewpoint of appropriately controlling vehicle movement.

[0171] [Third Embodiment]

[0172] Another embodiment of the present invention will now be described. For ease of description, the same reference numerals will be given to components having the same function as those described in the above embodiments, and their descriptions will not be repeated.

[0173] In this embodiment, ECU 1 further includes a driving state acquisition unit, which acquires information related to the vehicle's driving conditions. Then, ECU 1 causes one or both of the operation guidance state quantity conversion unit and the road surface guidance state quantity conversion unit to generate different damping forces required for operation guidance and road surface guidance, so that the driving conditions are transmitted to the driver based on the information acquired by the driving condition acquisition unit. Apart from this, this embodiment is the same as the first or second embodiment described above.

[0174] Figure 5 This is a block diagram schematically illustrating the functional configuration of the current value calculation unit according to this embodiment. For example... Figure 5 As shown, the current value calculation unit 600 includes an operation induction required current mapping 530 and a road surface induction required current mapping 540 instead of the required current mapping 520. Furthermore, an adder unit 510 is connected downstream of these mappings.

[0175] The current mapping 530 for operation induction obtains the damping force DampRQST required for operation induction from the operation induction state quantity conversion unit 300. inertia Furthermore, it acquires the damper velocity DampV (not shown), and then, based on this data, the operation induction required current mapping 530 determines the operation induction current value to be applied to the solenoid valve to control the damping force caused by the operation of the vehicle 900. The road surface induction required current mapping 540 acquires the road surface induction required damping force DampRQST from the road surface induction state quantity conversion unit 400. road Furthermore, the damper velocity DampV (not shown) is acquired, and based on this data, the road surface induced current mapping 540 determines the road surface induced current value to be applied to the solenoid valve to control the damping force caused by the road surface. The adder 510 calculates the sum of the operating induced current value and the road surface induced current value to calculate the current value applied to the suspension.

[0176] In this embodiment, the driving status acquisition unit acquires information about the vehicle's driving status. This information can be obtained from actual driving conditions or from changes in those conditions. The information can originate from, for example, various sensors. Furthermore, the information can be communication data that can be received by the ECU 1.

[0177] Furthermore, in this embodiment, ECU1 is configured to automatically determine the vehicle's driving or operating conditions, and automatically switch between the gain width of the gain included in the operation guidance state quantity conversion unit 300 and the gain width of the gain included in the road surface guidance state quantity conversion unit 400. For example, ECU1 is configured to change each of the gain widths included in the operation guidance state quantity conversion unit 300 and the gain widths included in the road surface guidance state quantity conversion unit 400 to a specific value, or switch the magnitude relationship of the aforementioned gain widths, based on a combination of vehicle driving condition information acquired by the driving condition acquisition unit. Furthermore, for example, when the operation guidance state quantity and the road surface guidance state quantity are the same, ECU1 can generate a relative magnitude relationship between the damping force required for operation guidance and the damping force required for road surface guidance based on the information acquired by the driving condition acquisition unit.

[0178] More specifically, suppose ECU1 determines, based on information acquired by the driving condition acquisition unit, that the driver may be drowsy. In this case, ECU1 determines the gain width of the operation guidance state quantity conversion unit 300 and the gain width of the road surface guidance state quantity conversion unit 400 based on the setpoints for actively transmitting information from the road surface. As a result, information such as that caused by uneven road surfaces is more clearly transmitted to the driver, thus encouraging the driver to wake up.

[0179] Furthermore, for example, ECU1 detects or predicts deterioration of road conditions based on the detection values ​​of various sensors or weather information such as rainfall on the data link, according to information about driving conditions. In this case, ECU1 determines the gain width of the operation-inducing state quantity conversion unit 300 and the gain width of the road-inducing state quantity conversion unit 400 based on the set value for the transmission of information from the road surface. Therefore, changes in road conditions caused by road surface humidity are reflected in the vehicle's maneuverability or ride comfort, and the driver can perceive the deterioration of road conditions.

[0180] When no information based on driving conditions is received to send to the driver, ECU 1 controls the vehicle's suspension according to the above embodiment, thereby achieving both driving feel and ride comfort.

[0181] In this embodiment, the ECU1 further includes a driving condition acquisition unit, which acquires information related to the vehicle's driving condition. The ECU1 causes one or both of the operation guidance state quantity conversion unit and the road surface guidance state quantity conversion unit to make the damping force required for road surface guidance and the damping force required for operation guidance different from each other, so that the driving condition is sent to the driver based on the information acquired by the driving condition acquisition unit. From the perspective of maintaining a proper and stable driving state of the vehicle, this configuration is more effective.

[0182] [Variation Example]

[0183] As can be clearly seen from the above description, by separating the operational cause and the road surface cause and setting the target damping force, the present invention can be configured for a wide range of situations, such as damping force control emphasizing operational feel or damping force control emphasizing the transmission of road conditions to passengers. The present invention is not limited to the above embodiments and various modifications can be made within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in different embodiments.

[0184] For example, the sensor values ​​described in the above embodiments are examples. In this invention, various sensor values ​​can be used depending on the configuration of the operation-induced state quantity estimation model 120 or the road-induced state quantity estimation model 220. For example, the damping force DampF can be detected based on the travel sensor installed in the vehicle. Furthermore, the yaw rate can be obtained by distinguishing the values ​​of the yaw angle sensor. Alternatively, the yaw rate can be obtained based on the values ​​of the lateral acceleration sensor.

[0185] Furthermore, the damper force DampF can be calculated each time by using the applied current I and the damper velocity DampV as variables, instead of obtaining the damper force DampF from the damping map described above.

[0186] Furthermore, the Kalman gain K can change over time. In this case, the time-varying Kalman gain K can be obtained by calculating the Kalman gain K as the optimal Kalman gain for each computation step, and simultaneously adjusting the state covariance of each state variable, the process noise covariance of each computational noise, and the covariance of the observations appropriately.

[0187] In the above embodiments, handling-inducing state quantities and road-inducing state quantities are estimated based on tire-related state quantities. In this invention, handling-inducing state quantities and road-inducing state quantities can be estimated based on other vehicle-related state quantities. For example, handling-inducing state quantities and road-inducing state quantities can be estimated based on sensors that more directly detect state quantities in the vehicle using existing technology. Examples of sensors that directly detect state quantities include tire pneumatic sensors that detect tire pneumatic pressure. Since increases and decreases in the value of the tire pneumatic sensor indicate tire deformation, tire travel displacement (TireST) can be detected. Furthermore, handling-inducing state quantities and road-inducing state quantities can be estimated based on different vehicle-related state quantities.

[0188] Furthermore, in this embodiment of the invention, even when the handling guidance state quantity and the road surface guidance state quantity are the same, the road surface guidance state quantity can be converted from the damping force required for road surface guidance and the damping force required for handling guidance to the damping force required for road surface guidance. In this case, the calculation result of the suspension control device (ECU 1) can be used for suspension control as is, or the calculation result can be not used for suspension control, and the calculation can be terminated when it is determined that the handling guidance state quantity and the road surface guidance state quantity are the same.

[0189] Furthermore, in embodiments of the present invention, as a substitute or addition for the variation of the gain width of the operation guidance state quantity conversion unit 300 and the gain width of the road surface guidance state quantity conversion unit 400 in the third embodiment described above, the gain width of the gain can be changed according to the driver's operation.

[0190] Furthermore, in the embodiments of the present invention, in the third embodiment described above, the current value calculation unit 600 further includes the gain of the operation induced current value and the gain of the road surface induced current value, and the gain width of these gains can be changed according to the information obtained by the driving condition acquisition unit.

[0191] Furthermore, in this embodiment of the invention, instead of the road surface induction state quantity conversion unit, the operation induction state quantity conversion unit can convert the operation induction state quantity into the damping force required for operation induction, so that the damping force required for road surface induction and the damping force required for operation induction are different.

[0192] More specifically, when the maneuvering guidance state quantity and the road surface guidance state quantity are the same, the maneuvering guidance state quantity conversion unit can convert the maneuvering guidance state quantity into the damping force required for maneuvering guidance, making the damping force required for maneuvering guidance different from the damping force required for road surface guidance. Furthermore, the maneuvering guidance state quantity conversion unit can convert the maneuvering guidance state quantity into the required damping force for maneuvering guidance such that the required damping force for maneuvering guidance is relatively smaller than the required damping force for road surface guidance, making the damping force required for road surface guidance different from the damping force required for maneuvering guidance. Moreover, the maneuvering guidance state quantity conversion unit can convert the maneuvering guidance state quantity into the required damping force for maneuvering guidance such that the required damping force for maneuvering guidance is relatively larger than the required damping force for road surface guidance, making the damping force required for road surface guidance different from the damping force required for maneuvering guidance. Even with such a functional configuration, the same effect as in the above embodiment can be obtained.

[0193] Furthermore, in this embodiment of the invention, instead of the ECU (suspension control unit), one or both of the operation guidance state quantity conversion unit and the road surface guidance state quantity conversion unit may be provided with a driving condition acquisition unit. Even with this form, it is possible to generate the relative magnitude relationship between the damping force required for operation guidance and the damping force required for road surface guidance based on the information acquired by the driving condition acquisition unit.

[0194] In this embodiment of the invention, the control block of ECU 1 (especially the operation guidance state quantity estimation unit 100 and the road guidance state quantity estimation unit 200) can be implemented by logic circuits (hardware) formed in integrated circuits (IC chips) or by software.

[0195] In the latter case, ECU 1 includes, for example, one or more processors, and also includes a recording medium, wherein a program for implementing each function is readablely stored by the processor. The processor reads the program from the recording medium and executes the program.

[0196] As a processor, a central processing unit (CPU) can be used, for example. As a recording medium, a "non-transitory tangible medium" such as read-only memory (ROM), magnetic tape, disk, card, semiconductor memory, programmable logic circuit, etc., can be used. In addition, random access memory (RAM) can be provided for loading the above-mentioned program.

[0197] The program can be provided to the computer via any transmission medium capable of transmitting the program (communication network, broadcast wave, etc.). One aspect of the invention can also be implemented as a data signal loaded onto a carrier wave, in which the program is embodied by electronic transmission.

Claims

1. A suspension control device that controls the operation of a vehicle's suspension, the suspension control device comprising: Operation-induced state quantity estimation unit estimates operation-induced state quantities that represent the behavior caused by the operation of the vehicle; A road surface guidance state quantity estimation unit estimates a road surface guidance state quantity that represents the behavior of the vehicle caused by the road surface on which the vehicle travels; The operation-induced state quantity conversion unit converts the operation-induced state quantity into the damping force required for operation induction by multiplying the operation-induced state quantity by a predetermined first coefficient. The road surface induction state quantity conversion unit converts the road surface induction state quantity into a damping force required for road induction by multiplying it by a predetermined second coefficient. When the operational induction state quantity is the same as the road surface induction state quantity, the road surface induction state quantity conversion unit converts the road surface induction state quantity into a damping force required for road induction, such that the magnitude of the damping force required for road induction is relatively different from the magnitude of the damping force required for operational induction. as well as The current value calculation unit determines the current value to be applied to the suspension by referring to the damping force required for operation induction, the damping force required for road surface induction, and the damper speed, which is the speed of the damper of the suspension.

2. The suspension control device according to claim 1, wherein, The current calculation unit uses a mapping to determine the current value to be applied to the suspension, the mapping taking into account the damping force required for operation induction, the damping force required for road surface induction, and the damper speed.

3. The suspension control device according to claim 1 or 2, wherein, When the operation-induced state quantity is the same as the road surface-induced state quantity, the road surface-induced state quantity conversion unit converts the road surface-induced state quantity into the damping force required for road surface induction, such that the magnitude of the damping force required for road surface induction is relatively greater than the magnitude of the damping force required for operation-induced induction.

4. The suspension control device according to claim 1 or 2, wherein, When the operation-induced state quantity is the same as the road surface-induced state quantity, the road surface-induced state quantity conversion unit converts the road surface-induced state quantity into the damping force required for road surface induction, such that the magnitude of the damping force required for road surface induction is relatively smaller than the magnitude of the damping force required for operation-induced induction.

5. A vehicle having a suspension controlled by a suspension control device according to claim 1 or 2.

6. A suspension control method for controlling the operation of a vehicle's suspension, comprising: Operation-induced state quantity estimation step: estimating operation-induced state quantities that represent the behavior caused by the operation of the vehicle; The road surface induced state quantity estimation step estimates the road surface induced state quantity that represents the behavior of the vehicle caused by the road surface on which the vehicle travels; The operation-induced state quantity conversion step converts the operation-induced state quantity estimated in the operation-induced state quantity estimation step into the operation-induced state quantity by multiplying it by a predetermined first coefficient. The road surface induced state quantity conversion step involves multiplying the road surface induced state quantity estimated in the road surface induced state quantity estimation step by a predetermined second coefficient to convert the road surface induced state quantity into the damping force required for road surface induction. When the operational induced state quantity is the same as the road surface induced state quantity, the road surface induced state quantity is converted into the damping force required for road surface induction, such that the magnitude of the damping force required for road surface induction is relatively different from the magnitude of the damping force required for operational induction. as well as The current value calculation step refers to the damping force required for operation induction converted in the operation induction state quantity conversion step, the damping force required for road induction converted in the road surface induction state quantity conversion step, and the damper speed, which is the speed of the vehicle's damper, to determine the current value to be applied to the suspension.

7. The suspension control method according to claim 6, wherein, In the current value calculation step, A mapping is used to determine the current value to be applied to the suspension, the mapping taking into account the damping force required for operation induction, the damping force required for road surface induction, and the damper speed.

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