Electrically powered suspension device

Abstract

The present application provides an electric suspension device, and reduces power consumption of the electric suspension device. An electric suspension control ECU (20) of an electric suspension device (10) includes: an electric actuator (12) provided for each of a plurality of wheels (TR); an acceleration sensor (S1) disposed for each electric actuator (12) and configured to detect a first acceleration (α1); and the electric suspension control ECU (20) configured to control each electric actuator (12) based on the first acceleration (α1). The electric suspension control ECU (20) is configured to reduce a control amount for the electric actuator (12) when a first speed (V1) of the first acceleration (α1) in a vertical direction is equal to or less than a predetermined speed (V1A).

Description

Technical Field

[0001] The invention relates to an electric suspension device. Background Art

[0002] Conventionally, there is known technology related to an electric suspension device that is mounted on a vehicle and driven by a motor.

[0003] For example, the electric suspension device described in Patent Document 1 describes providing an electric actuator on each of a plurality of wheels and controlling the electric actuator based on detection results of an acceleration sensor to thereby suppress transmission of vibrations applied to the plurality of wheels to the vehicle body.

[0004] Prior art literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-131395 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, in the electric suspension device described in Patent Document 1, the electric actuator is controlled based on the detection results of the acceleration sensor, so the electric actuator may be controlled to suppress acceleration that does not affect ride comfort. As a result, electric power may be wasted.

[0008] An object of the present invention is to reduce the power consumption of an electric suspension device.

[0009] Means for solving problems

[0010] One embodiment of the present invention is an electric suspension device comprising: an electric actuator, which is provided on each of a plurality of wheels; an acceleration sensor, which is arranged on each of the electric actuators and detects acceleration in the up-down direction; and a control device, which controls each of the electric actuators according to the up-down acceleration, wherein the control device reduces the control amount for the electric actuator when the up-down speed based on the up-down acceleration is below a specified speed.

[0011] In another aspect of the present invention, in the above-described electric suspension device, the control device reduces the control amount for the electric actuator when the acceleration direction of the front wheels and the acceleration direction of the rear wheels are the same direction.

[0012] In another aspect of the present invention, in the above-described electric suspension device, the control device increases a control amount for the electric actuator when the acceleration directions of the front wheels and the acceleration directions of the rear wheels are opposite to each other.

[0013] In other embodiments of the present invention, based on the above-mentioned electric suspension device, the control device corrects the acceleration of the left and right front wheels by subtracting the average value of the acceleration of the left and right rear wheels from the acceleration of the left and right front wheels, and the control device corrects the acceleration of the left and right rear wheels by subtracting the average value of the acceleration of the left and right front wheels from the acceleration of the left and right rear wheels, and the control device controls the electric actuator according to the corrected acceleration of each wheel.

[0014] Effects of the Invention

[0015] According to the present invention, the power consumption of the electric suspension device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a perspective view showing an example of the arrangement of an electric suspension device.

[0017] Figure 2 This is a diagram showing an example of the structure of an electric suspension device.

[0018] Figure 3 This is a diagram showing an example of processing by the electric suspension control ECU.

[0019] Description of labels

[0020] 1: Vehicle; 10: Electric suspension device; 12: Electric actuator; 12A: First electric actuator; 12B: Second electric actuator; 12C: Third electric actuator; 12D: Fourth electric actuator; 13: High-voltage line; 14: Signal line; 15: Low-voltage line; 16: Battery; 20: Electric suspension control ECU (control unit); 21A: Memory; 21B: Processor; 211: Correction unit; 212: Filter unit; 213: Control execution unit; 22: Inverter; 26: Boost circuit; 28: Drive circuit; 30: Connecting unit; 32: Inner tube; 34: Nut; 40: Outer tube; 42: Threaded shaft; 44: Bearing; 46: Motor; BD: Vehicle body; FA: Predetermined frequency; S1: Acceleration sensor; S2: Stroke sensor; S3: Rotation angle sensor; S4: Voltage sensor; ST: Stroke; TR: Vehicle wheel; V1: first speed (up and down direction speed); V1A: specified speed; VFL1: first left front wheel speed; VFR1: first right front wheel speed; VRL1: first left rear wheel speed; VRR1: first right rear wheel speed; V2: second speed; VFL2: second left front wheel speed; VFR2: second right front wheel speed; VRL2: second left rear wheel speed; VRR2: second right rear wheel speed; VH: high voltage; α1: first acceleration (up and down direction acceleration); αFL1: first left front wheel acceleration; αFR1: first right front wheel acceleration; αRL1: first left rear wheel acceleration; αRR1: first right rear wheel acceleration; α2: second acceleration; αFL2: second left front wheel acceleration; αFR2: second right front wheel acceleration; αRL2: second left rear wheel acceleration; αRR2: second right rear wheel acceleration; θ: rotation angle. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] [1. Structure of the electric suspension system]

[0023] Figure 1 It is a perspective view showing an example of the arrangement of the electric suspension device 10 . Figure 2 1 is a diagram showing an example of the structure of the electric suspension device 10 .

[0024] Reference Figure 1 and Figure 2 , the electric suspension device 10 will be described.

[0025] like Figure 1 As shown, the vehicle 1 includes a vehicle body BD, four wheels TR, and an electric suspension device 10. The electric suspension device 10 includes an electric actuator 12 and an electric suspension control ECU 20.

[0026] The electric actuator 12 is located outside the vehicle body BD. Specifically, the electric actuator 12 consists of a first electric actuator 12A, a second electric actuator 12B, a third electric actuator 12C, and a fourth electric actuator 12D. The first electric actuator 12A is located between the vehicle body BD and the right front wheel. The second electric actuator 12B is located between the vehicle body BD and the left front wheel. The third electric actuator 12C is located between the vehicle body BD and the right rear wheel. The fourth electric actuator 12D is located between the vehicle body BD and the left rear wheel.

[0027] The electric suspension control ECU (Electronic Control Unit) 20 controls the first to fourth electric actuators 12A to 12D and is connected to the first to fourth electric actuators 12A to 12D via a high-voltage line 13 , a signal line 14 , and a low-voltage line 15 .

[0028] High voltage line 13 will come from Figure 2 The high voltage VH power of the battery 16 is supplied to the first to fourth electric actuators 12A to 12D. The high voltage VH power is used for Figure 2 The high voltage VH is, for example, AC 33V to 37V.

[0029] Signal line 14 will Figure 2 Detection signals from the sensors S1 to S4 are transmitted to the electric suspension control ECU 20 .

[0030] Reference Figure 2 Sensors S1 to S4 will be described.

[0031] The low voltage line 15 will come from Figure 2 The low voltage VL power of the battery 16 is supplied to the first to fourth electric actuators 12A to 12D. Figure 2 The operation of the sensors S1 to S4 is shown. The low voltage VL is, for example, 5V DC.

[0032] In the following description, the electric suspension control ECU 20 may be referred to as the control ECU 20 for convenience.

[0033] The first to fourth electric actuators 12A to 12D have substantially the same structure. Therefore, hereinafter, the first to fourth electric actuators 12A to 12D may be referred to as electric actuators 12 when not being distinguished from each other.

[0034] Next, refer to Figure 2The structure of the electric actuator 12 will be described.

[0035] like Figure 2 As shown, the electric actuator 12 includes a coupling portion 30, an inner tube 32, and a nut 34 as components on the wheel TR side. Furthermore, the electric actuator 12 includes an outer tube 40, a threaded shaft 42, a bearing 44, and a motor 46 as components on the vehicle body BD side. The outer tube 40, bearing 44, and motor 46 are fixed to a chassis 48 disposed below the vehicle body BD.

[0036] The screw shaft 42 is supported by a bearing 44 and a nut 34. The inner surface of the nut 34 is screwed into a screw groove formed on the outer surface of the screw shaft 42 via the bearing.

[0037] The motor 46 rotates the threaded shaft 42, thereby moving the nut 34 in the vertical direction. When the nut 34 moves downward, the inner tube 32 moves downward. When the nut 34 moves upward, the inner tube 32 moves upward.

[0038] In this manner, the position of the inner tube 32 in the vertical direction relative to the outer tube 40 fixed to the chassis 48 of the vehicle body BD can be adjusted.

[0039] The connecting portion 30 is fixed to the steering knuckle (not shown) of the suspension system, thereby connecting to the wheel TR. When vibration is input to the connecting portion 30 from the wheel TR side, such as when upward acceleration is applied to the connecting portion 30, the inner tube 32 and the nut 34 move upward along with the outer tube 40. In this case, the motor 46 rotates the threaded shaft 42 in a direction that absorbs the upward acceleration, i.e., so that the inner tube 32 moves upward, thereby attenuating the vibration transmitted from the wheel TR to the vehicle body BD.

[0040] An acceleration sensor S1 , a stroke sensor S2 , a rotation angle sensor S3 , and a voltage sensor S4 are arranged in the electric actuator 12 .

[0041] The acceleration sensor S1 is fixed to the outer peripheral surface of the inner tube 32, for example, and detects the first acceleration α1 applied from the wheel TR to the coupling portion 30. In this embodiment, the acceleration sensor S1 detects the first acceleration α1 in the vertical direction on the sprung portion of the vehicle body BD.

[0042] The first acceleration α1 corresponds to an example of “up-down acceleration”.

[0043] The stroke sensor S2 is disposed at a position of the inner tube 32 facing the threaded shaft 42, and detects a stroke ST indicating the amount of downward movement of the nut 34. The stroke sensor S2 is constituted by a distance measuring sensor or the like.

[0044] The rotation angle sensor S3 is composed of a so-called resolver, a Hall element, or the like, and detects the rotation angle θ of the motor 46 .

[0045] The voltage sensor S4 detects a voltage V applied to the motor 46 . When the motor 46 is driven by electric power from the battery 16 , the voltage V indicates a high voltage VH supplied from the battery 16 via the high-voltage line 13 .

[0046] The first acceleration α1 , the stroke ST, the rotation angle θ, and the voltage V are output to the control ECU 20 .

[0047] like Figure 1 As shown, the acceleration sensor S1 located in the first electric actuator 12A detects the first right front wheel acceleration αFR1. Furthermore, the acceleration sensor S1 located in the second electric actuator 12B detects the first left front wheel acceleration αFL1. The acceleration sensor S1 located in the third electric actuator 12C detects the first right rear wheel acceleration αRR1. The acceleration sensor S1 located in the fourth electric actuator 12D detects the first left rear wheel acceleration αRL1.

[0048] like Figure 2 As shown, the first right front wheel acceleration αFR1, the first left front wheel acceleration αFL1, the first right rear wheel acceleration αRR1, and the first left rear wheel acceleration αRL1 are input to the control ECU 20. The first right front wheel acceleration αFR1, the first left front wheel acceleration αFL1, the first right rear wheel acceleration αRR1, and the first left rear wheel acceleration αRL1 respectively correspond to an example of the first acceleration α1.

[0049] [2. Electric Suspension Control ECU Structure]

[0050] The control ECU 20 controls the motor 46 via the inverter 22 based on the detection results of the acceleration sensor S1, the stroke sensor S2, the rotation angle sensor S3, and the voltage sensor S4. In the present embodiment, the control ECU 20 controls the motor 46 via the inverter 22 based on the first right front wheel acceleration αFR1, the first left front wheel acceleration αFL1, the first right rear wheel acceleration αRR1, and the first left rear wheel acceleration αRL1.

[0051] The control ECU 20 includes a memory 21A and a processor 21B.

[0052] The memory 21A is a storage device that nonvolatilely stores programs and data executed by the processor 21B. The memory 21A is composed of a magnetic storage device, a semiconductor storage element such as a flash ROM (Read Only Memory), or another type of nonvolatile storage device. The memory 21A may also include a RAM (Random Access Memory) that serves as a work area for the processor 21B. The memory 21A stores data processed by the control ECU 20 and control programs executed by the processor 21B.

[0053] The electric suspension control ECU 20 corresponds to an example of a “control device”.

[0054] The processor 21B may be composed of a single processor, or may be a configuration in which a plurality of processors function as the processor 21 B. The processor 21B executes a control program to control each unit of the electric suspension device 10 .

[0055] The control ECU 20 includes a correction unit 211, a filter unit 212, and a control execution unit 213. Specifically, the processor 21B of the control ECU 20 functions as the correction unit 211, the filter unit 212, and the control execution unit 213 by executing a control program.

[0056] The control ECU 20 calculates a first velocity V1 based on the first acceleration α1, and when the first velocity V1 is equal to or less than a predetermined velocity V1A, reduces the control amount for the electric actuator 12. Specifically, the control ECU 20 reduces components of the first velocity V1 below a predetermined frequency FA (e.g., 1 Hz) using, for example, a high-pass filter FLH.

[0057] The first speed V1 corresponds to an example of a “vertical speed”.

[0058] The control ECU 20 obtains the first velocity V1 by integrating the second acceleration α2 obtained by correcting the first acceleration α1. In the present embodiment, the control ECU 20 obtains the first velocity V1 by inputting the second acceleration α2 into the integration filter FLJ.

[0059] For the integral filter FLJ and the high-pass filter FLH, refer to Figure 3 Further explanation.

[0060] Furthermore, when the direction of the first acceleration α1 of the front wheels is the same as the direction of the first acceleration α1 of the rear wheels, the correction unit 211 of the control ECU 20 reduces the control amount for the electric actuator 12. In other words, when the direction of the first acceleration α1 of the front wheels is the same as the direction of the first acceleration α1 of the rear wheels, the correction unit 211 corrects the first acceleration α1 so as to reduce the control amount for the electric actuator 12.

[0061] Furthermore, when the direction of the first acceleration α1 of the front wheels is opposite to the direction of the first acceleration α1 of the rear wheels, the correction unit 211 of the control ECU 20 increases the control amount for the electric actuator 12. In other words, when the direction of the first acceleration α1 of the front wheels is opposite to the direction of the first acceleration α1 of the rear wheels, the correction unit 211 corrects the first acceleration α1 so as to increase the control amount for the electric actuator 12.

[0062] Furthermore, the correction unit 211 of the control ECU 20 corrects the first acceleration α1 of the left and right front wheels by subtracting the average value of the first acceleration α1 of the left and right rear wheels from the first acceleration α1 of the left and right front wheels. The correction unit 211 of the control ECU 20 corrects the first acceleration α1 of the left and right rear wheels by subtracting the average value of the first acceleration α1 of the left and right front wheels from the first acceleration α1 of the left and right rear wheels.

[0063] These processes of the correction unit 211 will be further described below.

[0064] The correction unit 211 corrects the first left front wheel acceleration αFL1, the first right front wheel acceleration αFR1, the first left rear wheel acceleration αRL1 and the first right rear wheel acceleration αRR1 by using the following formulas (1) to (4) to obtain the second left front wheel acceleration αFL2, the second right front wheel acceleration αFR2, the second left rear wheel acceleration αRL2 and the second right rear wheel acceleration αRR2.

[0065] In the following description, the first left front wheel acceleration αFL1, the first right front wheel acceleration αFR1, the first left rear wheel acceleration αRL1, and the first right rear wheel acceleration αRR1 may be referred to as "first acceleration α1" when no distinction is made between them. Furthermore, the second left front wheel acceleration αFL2, the second right front wheel acceleration αFR2, the second left rear wheel acceleration αRL2, and the second right rear wheel acceleration αRR2 may be referred to as "second acceleration α2" when no distinction is made between them.

[0066] In addition, the second left front wheel acceleration αFL2 represents the first left front wheel acceleration αFL1 after correction based on the formula (1).

[0067] αFL2=αFL1-K1×(αRL1+αRR1) / 2 (1)

[0068] The second right front wheel acceleration αFR2 represents the first right front wheel acceleration αFR1 after correction based on the formula (2).

[0069] αFR2=αFR1-K1×(αRL1+αRR1) / 2 (2)

[0070] The second left rear wheel acceleration αRL2 represents the first left rear wheel acceleration αRL1 after correction based on the formula (3).

[0071] αRL2=αRL1-K2×(αFL1+αFR1) / 2 (3)

[0072] The second right rear wheel acceleration αRR2 represents the first right rear wheel acceleration αRR1 after correction based on the formula (4).

[0073] αRR2=αRR1-K2×(αFL1+αFR1) / 2 (4)

[0074] The first coefficient K1 and the second coefficient K2 are respectively greater than 0 and less than 1.

[0075] Next, the effects of the correction performed by correction unit 211 will be described. First, the case where the direction of the first front wheel acceleration α1 is the same as the direction of the first rear wheel acceleration α1 will be described. For example, the case where the first left front wheel acceleration αFL1, the first right front wheel acceleration αFR1, the first left rear wheel acceleration αRL1, and the first right rear wheel acceleration αRR1 satisfy the following formula (4) will be described.

[0076] αFL1=αFR1=αRL1=αRR1 (4)

[0077] In this case, the second left front wheel acceleration αFL2, the second right front wheel acceleration αFR2, the second left rear wheel acceleration αRL2, and the second right rear wheel acceleration αRR2 are expressed by the following formula (5) and formula (6), respectively.

[0078] αFL2=αFR2=(1-K1)×αFL1 (5)

[0079] αRL2=αRR2=(1-K2)×αFL1 (6)

[0080] Since the first coefficient K1 and the second coefficient K2 are both greater than 0 and less than 1, the direction of the second acceleration α2 is the same as that of the first acceleration α1, and the absolute value of the second acceleration α2 is smaller than that of the first acceleration α1. In other words, by correcting the first acceleration α to the second acceleration α2, the control amount for the electric actuator 12 is reduced. Consequently, unnecessary power consumption on slopes and other conditions can be reduced.

[0081] Next, a case where the direction of the first acceleration α1 of the front wheels and the direction of the first acceleration α1 of the rear wheels are opposite to each other will be described. That is, a case where an acceleration in the pitch direction acts on the vehicle 1 .

[0082] For example, a case will be described where the first left front wheel acceleration αFL1, the first right front wheel acceleration αFR1, the first left rear wheel acceleration αRL1, and the first right rear wheel acceleration αRR1 satisfy the following formula (7).

[0083] αFL1=αFR1=-αRL1=-αRR1 (7)

[0084] In this case, the second left front wheel acceleration αFL2, the second right front wheel acceleration αFR2, the second left rear wheel acceleration αRL2, and the second right rear wheel acceleration αRR2 are expressed by the following formula (8) and formula (9), respectively.

[0085] αFL2=-αFR2=(1+K1)×αFL1 (8)

[0086] αRL2=-αRR2=(1+K2)×αFL1 (9)

[0087] Because the first coefficient K1 and the second coefficient K2 are both greater than 0 and less than 1, the direction of the second acceleration α2 is the same as that of the first acceleration α1, and the absolute value of the second acceleration α2 is greater than that of the first acceleration α1. In other words, by correcting the first acceleration α1 to the second acceleration α2, the control amount for the electric actuator 12 is increased. Consequently, the acceleration in the pitch direction of the vehicle 1 can be effectively suppressed.

[0088] Next, a case where the direction of the first acceleration α1 of the left front wheel and the direction of the first acceleration α1 of the right front wheel are opposite to each other will be described. In other words, a case where the acceleration in the roll direction acts on the vehicle 1 will be described.

[0089] For example, a case will be described where the first left front wheel acceleration αFL1, the first right front wheel acceleration αFR1, the first left rear wheel acceleration αRL1, and the first right rear wheel acceleration αRR1 satisfy the following formula (10).

[0090] αFL1=αRL1=-αFR1=-αRR1 (10)

[0091] In this case, the second left front wheel acceleration αFL2, the second right front wheel acceleration αFR2, the second left rear wheel acceleration αRL2, and the second right rear wheel acceleration αRR2 are expressed by the following formula (11) and formula (12), respectively.

[0092] αFL2=αRL2=-αFR2=-αRR2=αFL1 (11)

[0093] The direction of the second acceleration α2 is the same as that of the first acceleration α1, and the absolute value of the second acceleration α2 is also the same as that of the first acceleration α1. In other words, by correcting the first acceleration α1 to the second acceleration α2, the control amount for the electric actuator 12 remains unchanged. Therefore, the effect of suppressing the acceleration in the roll direction remains unchanged.

[0094] Figure 3 2 is a diagram showing an example of processing performed by the electric suspension control ECU 20 .

[0095] like Figure 3 As shown in FIG, the first acceleration α1 is corrected to the second acceleration α2 by the correction unit 211. Figure 3 In the following, the processing for the second left front wheel acceleration αFL2 will be described as an example of the second acceleration α2.

[0096] The filter unit 212 integrates the second left front wheel acceleration αFL2 to generate the first left front wheel speed VFL1. The filter unit 212 integrates the second left front wheel acceleration αFL2 using, for example, an integrating filter FLJ to generate the first left front wheel speed VFL1.

[0097] Figure 3 An example of the gain characteristic and phase characteristic of the integrating filter FLJ is shown.

[0098] The horizontal axis of the gain characteristic and the phase characteristic is frequency. The vertical axis of the gain characteristic is gain, and the vertical axis of the phase characteristic is phase. Curve G11 shows an example of the gain characteristic of the integrating filter FLJ, and curve G12 shows an example of the phase characteristic of the integrating filter FLJ.

[0099] Similarly, the filter unit 212 integrates the second right front wheel acceleration αFR2 to generate the first right front wheel speed VFR1, integrates the second left rear wheel acceleration αRL2 to generate the first left rear wheel speed VRL1, and integrates the second right rear wheel acceleration αRR2 to generate the first right rear wheel speed VRR1.

[0100] In the following description, the first left front wheel speed VFL1, the first right front wheel speed VFR1, the first left rear wheel speed VRL1, and the first right rear wheel speed VRR1 may be described as the first speed V1 when not distinguishing from each other.

[0101] Next, the filter unit 212 removes the low-frequency components of the first left front wheel speed VFL1 to generate the second left front wheel speed VFL2. The filter unit 212 removes the low-frequency components of the first left front wheel speed VFL1 using, for example, a high-pass filter FLH to generate the second left front wheel speed VFL2.

[0102] Figure 3 An example of the gain characteristic and phase characteristic of the high-pass filter FLH is shown.

[0103] The horizontal axis of the gain characteristic and the phase characteristic is frequency. The vertical axis of the gain characteristic is gain, and the vertical axis of the phase characteristic is phase. Curve G21 shows an example of the gain characteristic of the high-pass filter FLH, and curve G22 shows an example of the phase characteristic of the high-pass filter FLH.

[0104] exist Figure 3 In the high-pass filter FLH shown, for example, low-frequency components of 1 Hz or less of the first left front wheel speed VFL1 are removed to generate the second left front wheel speed VFL2.

[0105] Similarly, the filter unit 212 removes low-frequency components from the first right front wheel speed VFR1 to generate the second right front wheel speed VFR2, removes low-frequency components from the first left rear wheel speed VRL1 to generate the second left rear wheel speed VRL2, and removes low-frequency components from the first right rear wheel speed VRR1 to generate the second right rear wheel speed VRR2.

[0106] In the following description, the second left front wheel speed VFL2, the second right front wheel speed VFR2, the second left rear wheel speed VRL2, and the second right rear wheel speed VRR2 may be described as second speeds V2 when not distinguishing from each other.

[0107] To remove low-frequency components of the first velocity V1 below 1 Hz, the control variable of the electric actuator 12 corresponding to the low-frequency components of the first velocity V1, which have little impact on ride comfort, is reduced. In other words, when the first velocity V1 is below a predetermined velocity V1A, the control variable of the electric actuator 12 is reduced. This reduces unnecessary power consumption that has little impact on ride comfort.

[0108] The control execution unit 213 determines the control amount of the electric actuator 12 based on the second velocity V2 generated by the filter unit 212. Specifically, the control execution unit 213 determines the control amount of the first electric actuator 12A based on the second right front wheel speed VFR2. Furthermore, the control execution unit 213 determines the control amount of the second electric actuator 12B based on the second left front wheel speed VFL2. Furthermore, the control amount of the third electric actuator 12C is determined based on the second right rear wheel speed VRR2. Furthermore, the control amount of the fourth electric actuator 12D is determined based on the second left rear wheel speed VRL2.

[0109] Specifically, the speed of the motor 46 of the electric actuator 12 is determined based on the second speed V2. Figure 2 The direction of rotation and the speed of rotation of the threaded shaft 42 are shown.

[0110] [3. Structure and Effect]

[0111] As described above, the electric suspension control ECU 20 of the electric suspension device 10 of the present embodiment includes: an electric actuator 12, which is provided on each of the plurality of wheels TR; an acceleration sensor S1, which is arranged on each electric actuator 12 and detects a first acceleration α1; and the electric suspension control ECU 20, which controls each electric actuator 12 according to the first acceleration α1. When the first speed V1 based on the first acceleration α1 in the up and down direction is below the prescribed speed V1A, the electric suspension control ECU 20 reduces the control amount for the electric actuator 12.

[0112] According to this configuration, when the first speed V1 is equal to or lower than the predetermined speed V1A, the control amount for the electric actuator 12 is reduced. Therefore, by appropriately setting the predetermined speed V1A, unnecessary power consumption that has little effect on riding comfort can be reduced.

[0113] Furthermore, when the direction of the first acceleration α1 of the front wheels and the direction of the first acceleration α1 of the rear wheels are the same direction, the electric suspension control ECU 20 reduces the control amount for the electric actuator 12 .

[0114] According to this configuration, when the directions of the first acceleration α1 of the front wheels and the first acceleration α1 of the rear wheels are the same, the control amount for the electric actuator 12 is reduced. Therefore, unnecessary power consumption on slopes and the like can be reduced.

[0115] Furthermore, when the direction of the first acceleration α1 of the front wheels and the direction of the first acceleration α1 of the rear wheels are opposite to each other, the electric suspension control ECU 20 increases the control amount for the electric actuator 12 .

[0116] According to this configuration, when the directions of the first acceleration α1 of the front wheels and the first acceleration α1 of the rear wheels are opposite, the control amount for the electric actuator 12 is increased. Therefore, the acceleration in the pitch direction of the vehicle 1 can be effectively suppressed.

[0117] In addition, the electric suspension control ECU 20 corrects the first acceleration α1 of the left and right front wheels by subtracting the average value of the first acceleration α1 of the left and right rear wheels from the first acceleration α1 of the left and right front wheels, calculates the second acceleration α2 of the left and right front wheels, corrects the first acceleration α1 of the left and right rear wheels by subtracting the average value of the first acceleration α1 of the left and right front wheels from the first acceleration α1 of the left and right rear wheels, calculates the second acceleration α2 of the left and right rear wheels, and controls the electric actuator 12 according to the second acceleration α2 of each wheel.

[0118] With this configuration, the first acceleration α1 of the left and right front wheels is corrected by subtracting the average of the first acceleration α1 of the left and right rear wheels from the first acceleration α1 of the left and right front wheels, thereby calculating the second acceleration α2 of the left and right front wheels. Furthermore, the first acceleration α1 of the left and right rear wheels is corrected by subtracting the average of the first acceleration α1 of the left and right front wheels from the first acceleration α1 of the left and right rear wheels, thereby calculating the second acceleration α2 of the left and right rear wheels. The electric actuator 12 is then controlled based on the second acceleration α2 of each wheel.

[0119] Therefore, as reference Figure 2 As described above, unnecessary power consumption on slopes and the like can be reduced, and the acceleration in the pitch direction of the vehicle 1 can be effectively suppressed. The above configuration corresponds to the case where the first coefficient K1 and the second coefficient K2 in the above formulas (1) to (4) are both "1".

[0120] [4. Other Implementation Methods]

[0121] The present invention is not limited to the configurations of the above-described embodiments, and can be implemented in various forms without departing from the spirit and scope of the present invention.

[0122] For example, the above embodiment describes the removal of low-frequency components below 1 Hz of the first velocity V1, but the present invention is not limited to this. When the first velocity V1 is below the predetermined velocity V1A, the control amount of the electric actuator 12 may be reduced. For example, when the first velocity V1 is below 10 mm / s, the control amount of the electric actuator 12 may be reduced.

[0123] For example, in the above embodiment, the electric suspension control ECU 20 uses the integrating filter FLJ to integrate the second acceleration α2 to generate the first velocity V1. However, the present invention is not limited to this. The electric suspension control ECU 20 may simply calculate the first velocity V1 based on the second acceleration α2. For example, the electric suspension control ECU 20 may also calculate the velocity V1 by integrating the acceleration α2.

[0124] In the above embodiment, the first acceleration α1 is corrected using equations (1) to (4) to calculate the second acceleration α2. However, this is not limiting. When the direction of the first acceleration α1 of the front wheels is the same as the direction of the first acceleration α1 of the rear wheels, the control amount for the electric actuator 12 can be reduced. When the direction of the first acceleration α1 of the front wheels is the same as the direction of the first acceleration α1 of the rear wheels, for example, the second acceleration α2 can be calculated so that the magnitude of the second acceleration α2 is smaller than the magnitude of the first acceleration α1.

[0125] Furthermore, in the above embodiment, the second acceleration α2 is calculated by correcting the first acceleration α1 using equations (1) to (4), but the present invention is not limited to this. When the direction of the first acceleration α1 of the front wheels is opposite to the direction of the first acceleration α1 of the rear wheels, the control amount for the electric actuator 12 can be increased. When the direction of the first acceleration α1 of the front wheels is opposite to the direction of the first acceleration α1 of the rear wheels, for example, the second acceleration α2 can be calculated so that the magnitude of the second acceleration α2 is greater than the magnitude of the first acceleration α1.

[0126] Figure 2 At least a portion of each functional block shown may be implemented by hardware or by hardware and software, and is not limited to the configuration in which independent hardware resources are arranged as shown in the figure.

[0127] The control program executed by the processor 21B of the electric suspension control ECU 20 of the electric suspension device 10 is stored in the memory 21A, but the control program may be stored in an external HDD or the like.

[0128] The control method of the electric suspension control ECU 20 can be implemented by causing the processor 21B of the electric suspension control ECU 20 to execute a control program corresponding to the control method of the electric suspension control ECU 20. The control program can be recorded on a recording medium that is recorded in a computer-readable manner. The recording medium can use a magnetic recording medium, an optical recording medium, or a semiconductor storage device. Specifically, removable or fixed recording media such as a floppy disk, a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versatile Disc), a Blu-ray (registered trademark) Disc, a magneto-optical disk, a flash memory, and a card-type recording medium are listed. The recording medium can also be a non-volatile storage device such as a RAM, ROM, or HDD that is an internal storage device of the electric suspension device 10. The control program corresponding to the control method of the electric suspension control ECU 20 is stored in a server device, etc., and the control method of the electric suspension control ECU 20 can be implemented by downloading the control program from the server device to the electric suspension control ECU 20.

[0129] [5. Structure supported by the above-mentioned embodiment]

[0130] The above-mentioned embodiment supports the following structure.

[0131] (Structure 1) An electric suspension device, an electric actuator, which is provided on each of a plurality of wheels; an acceleration sensor, which is arranged on each of the electric actuators and detects acceleration in the up-down direction; and a control device, which controls each of the electric actuators according to the up-down acceleration, wherein the control device reduces the control amount for the electric actuator when the up-down speed based on the up-down acceleration is below a specified speed.

[0132] According to the electric suspension device of configuration 1, the vertical velocity is calculated based on the vertical acceleration, and the control amount of the electric actuator is reduced when the vertical velocity is below a predetermined velocity. Therefore, unnecessary power consumption that has little impact on ride comfort can be reduced.

[0133] (Structure 2) The electric suspension device according to Structure 1, wherein the control device reduces the control amount for the electric actuator when the direction of the acceleration of the front wheels and the direction of the acceleration of the rear wheels are the same direction.

[0134] According to the electric suspension device of configuration 2, when the acceleration directions of the front wheels and the rear wheels are the same, the control amount for the electric actuator is reduced, thereby reducing unnecessary power consumption on slopes and the like.

[0135] (Structure 3) The electric suspension device according to Structure 1 or Structure 2, wherein the control device increases the control amount for the electric actuator when the acceleration direction of the front wheels and the acceleration direction of the rear wheels are opposite.

[0136] According to the electric suspension device of configuration 3, when the acceleration directions of the front wheels and the acceleration directions of the rear wheels are opposite, the control amount of the electric actuator is increased. Therefore, the acceleration in the pitch direction of the vehicle can be effectively suppressed.

[0137] According to the electric suspension device of configuration 3, when the acceleration directions of the front wheels and the acceleration directions of the rear wheels are opposite, the control amount of the electric actuator is increased. Therefore, the acceleration in the pitch direction of the vehicle can be effectively suppressed.

[0138] (Structure 4) An electric suspension device according to any one of Structures 1 to 3, wherein the control device corrects the acceleration of the left and right front wheels by subtracting the average value of the left and right accelerations of the rear wheels from the acceleration of the left and right front wheels, corrects the acceleration of the left and right rear wheels by subtracting the average value of the left and right front accelerations from the acceleration of the left and right rear wheels, and controls the electric actuator according to the corrected accelerations of each wheel.

[0139] According to the electric suspension device of the fourth configuration, unnecessary power consumption on slopes and the like can be reduced, and the acceleration in the pitch direction of the vehicle can be effectively suppressed.

Claims

1. An electric suspension device comprising: an electric actuator provided at each of the plurality of wheels; an acceleration sensor disposed on each of the electric actuators to detect acceleration in the vertical direction; as well as a control device for controlling each of the electric actuators according to the acceleration in the vertical direction; The control device reduces the control amount for the electric actuator when the vertical speed based on the vertical acceleration is equal to or less than a predetermined speed. The control device corrects the acceleration of each of the left and right front wheels by subtracting an average value of the acceleration of each of the left and right rear wheels from the acceleration of each of the left and right front wheels. The control device corrects the acceleration of each of the left and right rear wheels by subtracting an average value of the acceleration of each of the left and right front wheels from the acceleration of each of the left and right rear wheels. The control device controls the electric actuator based on the corrected acceleration of each wheel.

2. The electric suspension device according to claim 1, wherein: The control device reduces the control amount for the electric actuator when the direction of the acceleration of the front wheels and the direction of the acceleration of the rear wheels are the same direction.

3. The electric suspension device according to claim 1 or 2, wherein: The control device increases a control amount for the electric actuator when a direction of acceleration of the front wheels and a direction of acceleration of the rear wheels are opposite to each other.

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