Attenuation force control device, attenuation force control system and method for correcting sensor unit

Abstract

To provide an attenuation force control device and an attenuation force control system which facilitate calibration of a sensor unit and can be easily installed on a vehicle, and a method for correcting a sensor unit which is suitable for the attenuation force control device and the attenuation force control system.SOLUTION: An attenuation force control device 1 includes a sensor unit 2 for detecting vibration at a predetermined position of a vehicle body B of a vehicle V, a control unit 3 for controlling attenuation force of a shock absorber which is provided between the vehicle body B and wheels W of the vehicle V and can adjust attenuation force on the basis of vibration information detected by the sensor unit 2, and a communication unit 5 which allows wireless communications with a portable terminal 30. The attenuation force control device is configured to perform calibration of the sensor unit 2 according to an instruction from the portable terminal 30.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a damping force control device, a damping force control system, and a method for correcting a sensor unit. [Background technology]

[0002] Conventionally, shock absorbers with adjustable damping force are configured with a shock absorber body that is interposed between the sprung and unsprung members of a vehicle and expands and contracts, and a damping valve that provides resistance to the flow of fluid filled within the shock absorber body and is driven by a solenoid to adjust the generated damping force, with the solenoid being controlled by a damping force control device that is specialized for controlling shock absorbers installed in the vehicle.

[0003] In order to optimize the damping force of the shock absorber according to the vehicle's driving conditions, the damping force control device is equipped with sensors that obtain various information to recognize the driving conditions, such as the vehicle's speed, sprung acceleration, and unsprung acceleration, and a calculation device that calculates the damping force that the shock absorber should generate based on the information from the sensors, and supplies current to the solenoid of the damping valve so that the shock absorber generates the calculated damping force.

[0004] In such a system, in order to suppress vibrations of the vehicle body, the damping force control device calculates the vertical speed of the vehicle body at four locations directly above the wheels from the acceleration obtained from three sensors installed on the vehicle body, multiplies the vertical speed of the vehicle body by the skyhook damping coefficient to obtain the target damping force required for the shock absorbers installed at each of the four wheels to suppress vibrations of the vehicle body, and controls the damping force of each shock absorber to achieve the target damping force (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2024-015541 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned system, if the acceleration obtained by the sensor does not exactly match the actual vertical acceleration of the vehicle body, the damping force generated by the shock absorber will be too large or too small, reducing the effect of suppressing vehicle body vibration. Therefore, the sensor must be installed accurately in a predetermined position on the vehicle body, and sensor calibration is also essential.

[0007] However, when the damping force control device is not originally attached to the vehicle and the user installs the damping force control device on the vehicle, i.e., when the damping force control device is retrofitted, the sensor installation position relative to the vehicle body will vary, and the sensor calibration work will also need to be performed using a dedicated operating device for the damping force control device, making the calibration work very complicated.

[0008] Therefore, the present invention aims to provide a damping force control device and a damping force control system that can easily calibrate the sensor unit and can be easily installed on a vehicle, and to provide a method for correcting the sensor unit that is suitable for these damping force control devices and damping force control systems. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the damping force control device of the present invention comprises a sensor unit that detects vibrations at a predetermined position on the vehicle body, a control unit that controls the damping force of a damping force adjustable shock absorber installed between the vehicle body and the wheels based on vibration information detected by the sensor unit, and a communication unit that can communicate wirelessly with a mobile terminal, and is configured to calibrate the sensor unit based on instructions from the mobile terminal.

[0010] With a damping force control device configured in this manner, the user can easily instruct calibration of the sensor unit in the damping force control device using a mobile terminal, including smart devices such as smartphones and tablet terminals that the user carries with them on a daily basis and is familiar with operating, without using a dedicated operating device.In addition, since the calibration can correct the vibration information detected by the sensor unit, the sensor unit can be installed at any position on the vehicle body, making installation in the vehicle easy.

[0011] In addition, the damping force control system of the present invention comprises a sensor unit that detects vibrations at a predetermined position on the vehicle body, a control unit that controls the damping force of a damping force adjustable shock absorber installed between the vehicle body and the wheel based on vibration information detected by the sensor unit, a damping force control device having a communication unit capable of wireless communication, and a mobile terminal that has an inertial measurement unit and is capable of wireless communication with the damping force control device, and is configured to calibrate the sensor unit based on the error between the vibration information detected by the sensor unit and the vibration information detected by the mobile terminal.

[0012] With a damping force control system configured in this manner, the vibration information of the sensor unit can be corrected so that vibration information at a specified position on the vehicle body can be obtained using a mobile terminal, making calibration work extremely easy.In addition, the sensor unit can be installed at any position on the vehicle body, making it easy to install the damping force control device on the vehicle.

[0013] In addition, the damping force control system of the present invention comprises a sensor unit that detects vibrations at a predetermined position on the vehicle body, a control unit that controls the damping force of a damping force adjustable shock absorber installed between the vehicle body and the wheels based on vibration information detected by the sensor unit, a damping force control device having a communication unit capable of wireless communication, and a mobile terminal that has a touch panel and is capable of wireless communication with the damping force control device, and the mobile terminal has a position input unit that is displayed on the touch panel and allows the installation position of the sensor unit relative to the vehicle body to be input, and is configured to calibrate the sensor unit based on the installation position input using the position input unit.

[0014] According to the damping force control system configured in this manner, the installation position of the sensor unit relative to the vehicle body can be input using a mobile terminal, and the sensor unit can be calibrated by understanding the geometric error between the predetermined value of the vehicle body and the installation position of the sensor unit, making the calibration work extremely easy, and since the sensor unit can be installed in any position on the vehicle body, it also makes it easy to install the damping force control device in the vehicle. Furthermore, not only can the calibration be performed using a mobile terminal, eliminating the need for dedicated equipment, but also because instructions can be given to the user from the mobile terminal during the calibration work, so even users with little knowledge of calibration can easily perform the calibration work.

[0015] Furthermore, the damping force control system may be configured to calibrate the sensor unit with the mobile device installed at a predetermined position on the vehicle body. With this damping force control system configured in this manner, the sensor unit can be calibrated easily and accurately using the detection results of the inertial measurement unit of the mobile device.

[0016] Furthermore, the sensor unit correction method of the present invention is a sensor unit correction method for calibrating a sensor unit that detects three-axial acceleration in the forward / backward, left / right, and up / down directions and three-axial angular velocities in the pitch, roll, and yaw directions at a predetermined position on the vehicle body, and includes a procedure for calculating a rotation matrix that corrects the attitude of the sensor unit relative to the vehicle body based on the detection results of the three-axial acceleration detected by the sensor unit when the vehicle is parked on a level road surface and the detection results of the three-axial acceleration detected by the sensor unit when the vehicle is moving straight, and a procedure for calculating a correction coefficient that corrects the three-axial angular velocities and three-axial accelerations detected by the sensor unit to the three-axial angular velocities and three-axial accelerations at the predetermined position based on the error between the three-axial angular velocities and three-axial accelerations detected by a mobile terminal installed at the predetermined position and the three-axial angular velocities and three-axial accelerations detected by the sensor unit, or the geometric error between the installation position of the sensor unit relative to the vehicle body specified by the mobile terminal and the predetermined position.

[0017] According to the sensor unit correction method configured in this manner, corrections are made to align the acceleration detection axis of the sensor unit with the front-to-back, left-to-right, and top-to-bottom directions of the vehicle body, and corrections are made for angular velocity and acceleration that arise due to geometric errors between the installation position of the sensor unit and a specified position.Therefore, regardless of the installation position of the sensor unit, calibration of the sensor unit can be easily performed using a mobile terminal, and installation of the damping force control device in the vehicle is also made easy, making it ideal for damping force control devices and damping force control systems. [Effects of the Invention]

[0018] As described above, according to the damping force control device and damping force control system of the present invention, the sensor unit can be easily calibrated and can be easily installed on a vehicle. Furthermore, the sensor unit correction method is optimal for the damping force control device and damping force control system. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing a damping force control system and a damping force control device according to an embodiment applied to a vehicle; [Figure 2] FIG. 2 is a schematic cross-sectional view of a shock absorber. [Figure 3] 1 is a diagram illustrating a configuration of a damping force control device according to an embodiment. [Figure 4] FIG. 2 is a diagram showing a configuration of a current control unit in the damping force control device. [Figure 5] FIG. 2 is a diagram illustrating a configuration of a mobile terminal in the damping force control system according to the embodiment. [Figure 6] FIG. 3 is a diagram showing an initial screen of a touch panel of a mobile terminal in the damping force control system according to the embodiment. [Figure 7] 10 is a flowchart showing a procedure for a sensor attitude setting process in the damping force control device and the mobile terminal. [Figure 8] 10 is a flowchart showing a procedure for a sensor position setting process in the damping force control device and the mobile terminal. [Figure 9]10 is a diagram showing a position input section displayed on a touch panel of a mobile terminal in the damping force control system according to the embodiment; FIG. [Figure 10] 10 is a diagram showing an adjustment section displayed on a touch panel of a mobile terminal in the damping force control system according to the embodiment; FIG. [Figure 11] 10 is a flowchart showing a procedure for a process of transmitting setting information in a damping force control system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be described below based on the embodiments shown in the drawings. As shown in Fig. 1, a damping force control device 1 in one embodiment is configured to include a sensor unit 2 that detects vibrations at predetermined positions on a body B of a vehicle V, a control unit 3 that controls the damping force of an adjustable shock absorber D provided between the body B and wheels W of the vehicle V based on vibration information detected by the sensor unit 2, and a communication unit 5 that can wirelessly communicate with a mobile terminal 30. A damping force control system S in one embodiment is configured to include the damping force control device 1 and the mobile terminal 30. The damping force control device 1 in this embodiment controls four shock absorbers D that are respectively interposed between the body B of the vehicle V and the front, rear, left, and right wheels W of the vehicle body B.

[0021] First, we will explain the shock absorber D that is the object to be controlled by the damping force control device 1. As shown in Fig. 2, the shock absorber D includes a cylindrical cylinder 6, a piston 7 slidably inserted into the cylinder 6, a rod 8 inserted into the cylinder 6 so as to be axially movable and connected to the piston 7, an extension-side chamber R1 and a compression-side chamber R2 that are partitioned by the piston 7 within the cylinder 6 and filled with a liquid such as hydraulic oil, an intermediate cylinder 9 that covers the outer periphery of the cylinder 6 and forms an annular gap between it and the cylinder 6, and an outer cylinder 10 that covers the outer periphery of the intermediate cylinder 9 and forms an annular reservoir R that is filled with gas and liquid between it and the intermediate cylinder 9. The shock absorber D is provided with: a rectifying passage 11 that communicates between the expansion-side chamber R1 and the compression-side chamber R2 and allows only the flow of liquid from the compression-side chamber R2 to the expansion-side chamber R1 with almost no resistance; a suction passage 12 that communicates between the compression-side chamber R2 and the reservoir R and allows the flow of liquid from the reservoir R to the compression-side chamber R2 with almost no resistance; a damping passage 13 that communicates between the expansion-side chamber R1 and the reservoir R via a gap between the cylinder 6 and the intermediate tube 9; and a damping force adjusting unit 15 that can adjust the damping force generated by the shock absorber D in response to a command from the damping force control device 1.

[0022] In this embodiment, the damping force adjusting section 15 is a solenoid valve provided midway through the damping passage 13 .

[0023] As shown in the figure, the damping force adjustment unit 15 is configured to include, for example, a valve body 15a provided midway through the damping passage 13, a spring 15b that biases the valve body 15a so as to block the damping passage 13, and a solenoid 15c that generates a thrust force that counteracts the spring 15b when current is applied, and the valve opening pressure can be changed according to the amount of current supplied to the solenoid 15c.

[0024] When the pressure in the extension-side chamber R1 upstream of the damping passage 13 acting on the valve body 15a exceeds the relief pressure (valve-opening pressure) of the damping force adjustment unit 15, this pressure and the force of the solenoid 15c pressing on the valve body 15a overcome the force of the spring 15b biasing the valve body 15a, and the valve body 15a compresses the spring 15b, causing the damping force adjustment unit 15 to open the damping passage 13.

[0025] Furthermore, in the damping force adjusting unit 15, increasing the amount of current supplied to the solenoid 15c increases the thrust generated by the solenoid 15c. Therefore, when the amount of current supplied to the solenoid 15c is maximized, the valve-opening pressure in the damping force adjusting unit 15 is minimized, and conversely, when no current is supplied to the solenoid 15c at all, the valve-opening pressure in the damping force adjusting unit 15 is maximized. Note that the damping force adjusting unit 15 may be configured to maximize the valve-opening pressure when the amount of current to the solenoid 15c is maximized.

[0026] Although the damping force adjusting unit 15 is capable of adjusting the valve opening pressure as described above, it may also be capable of adjusting the flow path area by applying thrust generated by the damping force adjusting unit 15c to the valve element 15a. As described above, the damping force adjusting unit 15 is only required to be able to adjust the damping force generated by the shock absorber D by changing the resistance to the flow of liquid passing through the damping passage 13 in response to a command from the damping force control device 1. Therefore, instead of a solenoid valve, the damping force adjusting unit 15 may be a valve using a stepping motor, or, if the liquid filled in the shock absorber D is an electrorheological fluid, a magnetorheological fluid, or an electromagnetic rheological fluid, it may be provided with a device that applies an electric field or a magnetic field to the liquid passing through the damping passage 13 to adjust the resistance to the flow of liquid passing through the damping passage 13. Furthermore, the damping force adjusting unit 15 may be capable of adjusting the damping force during extension and compression of the shock absorber D, or may be capable of adjusting the damping force during either extension or compression.

[0027] In the shock absorber D configured as described above, during an extension operation of the shock absorber D in which the rod 8 moves upward in FIG. 2 relative to the cylinder 6, liquid moves from the extension-side chamber R1, which is compressed by the piston 7 rising in the cylinder 6, to the reservoir R via the damping passage 13 and the damping force adjustment unit 15. Therefore, the pressure in the extension-side chamber R1 rises and becomes equal to the valve-opening pressure of the damping force adjustment unit 15. Furthermore, during an extension operation of the shock absorber D, liquid is supplied from the reservoir R via the suction passage 12 to the compression-side chamber R2, whose volume is expanded by the piston 7 rising in the cylinder 6, so that the pressure in the compression-side chamber R2 becomes approximately equal to the pressure in the reservoir R. Therefore, the pressure in the extension-side chamber R1 becomes higher than the pressure in the compression-side chamber R2 by the valve-opening pressure of the damping force adjustment unit 15, and the shock absorber D generates a damping force that hinders the extension operation. Since the valve opening pressure of the damping force adjusting section 15 changes depending on the amount of current supplied to the solenoid 15c, the damping force during the expansion operation of the shock absorber D can be adjusted according to the amount of current supplied to the solenoid 15c.

[0028] On the other hand, when the shock absorber D is contracting and the rod 8 moves downward in FIG. 2 relative to the cylinder 6, liquid moves from the compression-side chamber R2, which is compressed by the piston 7 moving downward in the cylinder 6, to the expanding extension-side chamber R1 via the rectification passage 11. When the shock absorber D is contracting, an excess of liquid corresponding to the volume of the rod 8 entering the cylinder 6 is created inside the cylinder 6, and the excess liquid is discharged from the cylinder 6 to the reservoir R via the damping passage 13 and the damping force adjuster 15. Therefore, the pressures in the extension-side chamber R1 and the compression-side chamber R2 in the cylinder 6 both rise and become equal to the valve opening pressure of the damping force adjuster 15, but because the pressure-receiving area of ​​the piston 7 facing the compression-side chamber R2 is larger than the pressure-receiving area of ​​the piston 7 facing the extension-side chamber R1 by the cross-sectional area of ​​the rod 8, the shock absorber D generates a damping force that suppresses contraction. Since the valve opening pressure of the damping force adjusting section 15 changes depending on the amount of current supplied to the solenoid 15c, the damping force during the contraction operation of the shock absorber D can be adjusted according to the amount of current supplied to the solenoid 15c.

[0029] The configuration of the shock absorber D is merely an example and is not limited to the above configuration. Any configuration may be used as long as the damping force adjuster 15 is capable of generating a damping force that applies resistance to the flow of liquid and prevents the extension and contraction of the shock absorber D. Therefore, the shock absorber D of this embodiment is configured as a uniflow type that includes a reservoir R and in which liquid circulates one-way through the expansion-side chamber R1, the compression-side chamber R2, and the reservoir R in that order. However, the shock absorber D may be configured as a biflow type in which liquid flows back and forth between the expansion-side chamber R1 and the compression-side chamber R2 during expansion and contraction. When the shock absorber D is configured as a biflow type, if a damping passage connecting the expansion-side chamber R1 and the compression-side chamber R2 allows liquid to flow from the expansion-side chamber R1 to the compression-side chamber R2 and liquid to flow from the compression-side chamber R2 to the expansion-side chamber R1, a damping force adjuster may be provided in the damping passage. Furthermore, when the shock absorber D is configured as a bi-flow type and is provided with an extension side damping passage that allows liquid to flow only from the extension side chamber R1 to the compression side chamber R2 and a compression side damping passage that allows liquid to flow only from the compression side chamber R2 to the extension side chamber R1, a damping force adjusting device may be provided in both the extension side damping passage and the compression side damping passage, or a damping force adjusting device may be provided in only one of the extension side damping passage and the compression side damping passage.

[0030] The shock absorber D configured in this manner is interposed between the vehicle body B and the wheel W of the vehicle V, with the cylinder 6 attached to a knuckle or suspension arm that holds the wheel W and connected to the wheel W as an unsprung member, and the rod 8 connected to the vehicle body B as a sprung member. The shock absorber D expands and contracts due to vibrations input from the road surface while the vehicle V is traveling, generating a damping force that suppresses vibrations of the vehicle body B.

[0031] Next, the damping force control device 1 will be described. As shown in Fig. 3, the damping force control device 1 includes a sensor unit 2 that detects vibrations of a vehicle body B of a vehicle V, a control unit 3 that calculates a target damping force based on vibration information detected by the sensor unit 2, a current control unit 16 that controls the current supplied to a damping force adjusting unit 15 in a shock absorber D based on the target damping force calculated by the control unit 3, and a communication unit 5 that can wirelessly communicate with a mobile terminal 30. In addition, in the damping force control device 1 of this embodiment, the sensor unit 2, the control unit 3, the communication unit 5, and the current control unit 16 are housed in a single housing 20, and the housing 20 is installed in the passenger compartment of the vehicle V.

[0032] Each component of the damping force control device 1 will be described in detail below. In this embodiment, the sensor unit 2 is an inertial measurement device that detects angular velocities around the three axes of the vehicle body B (front-rear, left-right, and up-down), i.e., three angular velocities in the roll direction, pitch direction, and yaw direction of the vehicle body B, and accelerations around the three axes of the vehicle body B (front-rear, left-right, and up-down), as vibration information at a predetermined position of the vehicle body B. The sensor unit 2 is housed in a housing 20 and installed on the vehicle body B together with the housing 20. Note that it is sufficient for the sensor unit 2 to detect vibration information of the vehicle body B required for the damping force control device 1 to control the damping force. Therefore, for example, if the damping force control device 1 requires only the acceleration of the vehicle body B in the up-down direction, the sensor unit 2 may detect only the acceleration of the vehicle body B in the up-down direction. Furthermore, although the sensor unit 2 is housed in the housing 20 in the damping force control device 1 of this embodiment, it may also be installed on the vehicle body B separately from the housing 20.

[0033] The housing 20 is box-shaped and houses the sensor unit 2, the control unit 3, and the communication unit 5 inside. Although not shown, the characters "front" and "rear" are displayed near two opposing sides in the front-to-rear direction of the rectangular top surface of the housing 20, and the characters "right" and "left" are displayed near two opposing sides in the left-to-right direction of the rectangular top surface. The sensor unit 2 is housed in the housing 20 so that the detection axis of acceleration in the front-to-rear direction coincides with the front-to-rear direction of the housing 20, the detection axis of acceleration in the left-to-right direction coincides with the left-to-right direction of the housing 20, the detection axis of acceleration in the up-to-down direction coincides with the up-to-down direction of the housing 20, the direction of the detected roll angular velocity coincides with the direction of rotation about the front-to-rear direction of the housing 20 as an axis, the direction of the detected pitch angular velocity coincides with the direction of rotation about the left-to-right direction of the housing 20 as an axis, and the direction of the detected yaw angular velocity coincides with the direction of rotation about the up-to-down direction of the housing 20 as an axis.

[0034] Therefore, when a user of the damping force control device 1 installs the housing 20 near the center of the vehicle body inside the vehicle cabin, relying on the indications of "front," "rear," "left," and "right" on the top surface of the housing 20, and aligns the front, rear, left, right, and top and bottom of the housing 20 with the front, rear, left, right, and top and bottom of the vehicle body B, the sensor unit 2 can detect three angular velocities in the roll direction, pitch direction, and yaw direction at the installation position where the housing 20 is installed relative to the vehicle body B, and accelerations along the three axes of the front, rear, left, right, and top and bottom of the vehicle body B. In reality, the installation position of the sensor unit 2 may not coincide with a predetermined position on the vehicle body B, and the installation posture of the sensor unit 2 may not be horizontal when the vehicle V is stopped on a horizontal road surface. In this case, the angular velocities and accelerations detected by the sensor unit 2 may be corrected by calibration so that they coincide with the angular velocities and accelerations at the actual predetermined position of the vehicle body B. In the damping force control device 1 of this embodiment, the predetermined position of the sensor unit 2 is the center of gravity of the vehicle body B, and is calibrated so as to be able to detect the three-axial angular velocity and three-axial acceleration at the center of gravity of the vehicle body B. In the damping force control device 1 of this embodiment, the sensor unit 2 is configured to detect the angular velocity and acceleration at the center of gravity of the vehicle body B in order to control the damping force of the shock absorbers D installed on each of the four wheels, grasp the overall vibration of the vehicle body B, and suppress the vibration of the vehicle body B; however, the predetermined position may be set at a position other than the center of gravity as long as it is suitable for control by the damping force control device 1.

[0035] The indication of front, rear, left, and right displayed on the housing 20 may be affixed by engraving, pasting a piece of paper indicating the front, rear, left, and right, printing, or the like. If the housing 20 is manufactured by injection molding or the like using synthetic resin, the characters for front, rear, left, and right may be formed using a mold. Since it is sufficient to identify the front, rear, left, and right of the housing 20, only one of the characters for front, rear, left, and right may be displayed instead of all the characters for front, rear, left, and right. Symbols or numbers may be displayed instead of the characters for front, rear, left, and right. If the shape of the housing 20 allows for the identification of front, rear, left, right, and up and down, the indication of characters or symbols may be omitted. The indication on the housing 20 may be omitted because the angular velocities and accelerations detected by the sensor unit 2 are corrected by the calibration. However, it is preferable to indicate the indication on the housing 20 because, when the user installs the housing 20 in the direction of the vehicle body B according to the indication, the detection axis of the sensor unit 2 roughly coincides with the front, rear, left, right, and up and down of the vehicle body B.

[0036] The communication unit 5 is equipped with an antenna unit (not shown) and is capable of two-way communication with the mobile terminal 30. In this embodiment, wireless communication conforming to the IEEE802.15 standard is performed, but as long as communication with the mobile terminal 30 is possible, in addition to wireless communication conforming to the above standard, wireless LAN (Local Area Network) communication conforming to the IEEE802.11 standard may also be performed.

[0037] 5, the mobile terminal 30 is a highly portable terminal such as a smartphone or tablet PC, and includes an inertial measurement unit 30b housed in a housing 30a and capable of detecting triaxial angular velocity and triaxial acceleration, a touch panel 30c mounted on the housing 30a for displaying images and receiving user input, a transceiver 30d housed in the housing 30a and serving as a communication unit capable of wireless communication with external devices, a memory 30e housed in the housing 30a as a storage unit, a processing unit 30f housed in the housing 30a for controlling the various components of the mobile terminal 30 by executing a program, a GPS (Global Positioning System) receiver 30g, and a bus 30h communicatively connecting these components, thereby enabling the mobile terminal 30 to obtain its own location information. The inertial measurement unit 30b may be a unit that detects only triaxial acceleration without detecting triaxial angular velocity. Moreover, the mobile terminal 30 may be provided with a receiver that receives signals that can be used for positioning, such as a Global Navigation Satellite System (GNSS), instead of the GPS receiver 30g.

[0038] The mobile terminal 30 and the damping force control device 1 can exchange information with each other via the transceiver 30d and the communication unit 5. When an application program for setting parameters of the damping force control device 1 is started by an operator, the mobile terminal 30 becomes capable of communicating with the damping force control device 1 and can set parameters in the damping force control device 1.

[0039] The control unit 3 includes an acceleration calculation unit 3a that calculates the vertical acceleration directly above the four wheels W of the vehicle body B from the three angular velocities and three accelerations of the vehicle body B detected by the sensor unit 2, a target damping force calculation unit 3b that calculates the target damping force from the vertical accelerations of the four locations of the vehicle body B calculated by the acceleration calculation unit 3a, and a parameter setting unit 3c that sets parameters necessary for the calculation processing in the target damping force calculation unit 3b.

[0040] The acceleration calculation unit 3a calculates the vertical acceleration directly above the four wheels W of the vehicle body B from the three angular velocities and three accelerations at the installation position of the vehicle body B detected by the sensor unit 2. Since the detection axes for detecting the three-axial acceleration of the sensor unit 2 may not be perfectly aligned with the front-rear, left-right, and up-down directions of the vehicle body B and the sensor unit 2 may not be installed on the vehicle body B so as to coincide with the center of gravity of the vehicle body B, the acceleration calculation unit 3a corrects the three angular velocities and accelerations detected by the sensor unit 2 to calculate the vertical acceleration directly above the four wheels W of the vehicle body B, and calculates the three angular velocities and accelerations at the center of gravity position of the vehicle body B.

[0041] In addition, the acceleration calculation unit 3a corrects the three angular velocities and accelerations detected by the sensor unit 2 to obtain three angular velocities and accelerations at the center of gravity of the vehicle body B, and then obtains the vertical accelerations directly above the four wheels W of the vehicle body B from these obtained angular velocities and accelerations.

[0042] Specifically, the acceleration calculation unit 3a calculates the vertical acceleration directly above the four wheels W of vehicle body B from information on the tread and wheelbase of vehicle V and the center of gravity position of vehicle body B. If the positions directly above the four wheels W of vehicle body B and the center of gravity position are known, the vertical acceleration directly above the four wheels W of vehicle body B can be calculated from the three angular velocities and acceleration at the center of gravity position of vehicle body B. If the center of gravity position of vehicle body B and the tread and wheelbase of vehicle V are known, the relationship between the center of gravity position of vehicle body B and the positions directly above the four wheels W of vehicle body B can be determined, so the acceleration calculation unit 3a can calculate the vertical acceleration directly above the four wheels W of vehicle body B from the tread and wheelbase of vehicle V, information on the center of gravity position of vehicle body B, and the three angular velocities and acceleration at the center of gravity position of vehicle body B.

[0043] The tread and wheelbase of vehicle V and the position of the center of gravity of vehicle body B can be obtained from the specification information of vehicle V, and the tread and wheelbase of vehicle V on which the damping force control device 1 is mounted and the position of the center of gravity of vehicle body B can be input from a mobile terminal 30 described later. Since it may be difficult for a user who is not familiar with vehicle V to access the specification information of vehicle V, it may be possible to enable the mobile terminal 30 to obtain information on the tread, wheelbase and position of the center of gravity of vehicle body B by selecting the manufacturer and model of vehicle V in an application program for setting parameters of the damping force control device 1 executed by the mobile terminal 30 described later, and then send that information to the damping force control device 1. Furthermore, if the damping force control device 1 has specification information corresponding to the vehicle model and body type stored in advance in a memory (described later) in the hardware constituting the control unit 3, the application program may be executed to receive input of information about the vehicle model and body type of the vehicle V from the mobile terminal 30, the damping force control device 1 may select a tread, wheelbase, and center of gravity position that are compatible with the input manufacturer and vehicle model, and the acceleration calculation unit 3a may use the selected tread, wheelbase, and center of gravity position to calculate the vertical accelerations directly above the four wheels W of the vehicle body B. Furthermore, although this will be somewhat inaccurate, the acceleration calculation unit 3a may also calculate three angular velocities and accelerations at the center of gravity position of the vehicle body B using information about the tread, wheelbase, and center of gravity position of the vehicle body B, and then calculate the vertical accelerations directly above the four wheels W of the vehicle body B from the calculated angular velocities and accelerations.

[0044] In this embodiment, in order to perform skyhook control, the target damping force calculation unit 3b integrates or filters the vertical acceleration of the vehicle body B directly above the four wheels W calculated by the acceleration calculation unit 3a to calculate the vertical velocity of the vehicle body B directly above the four wheels W, and multiplies each of the vertical velocities of the vehicle body B directly above the four wheels W by a skyhook damping coefficient to calculate the skyhook damping force that should be generated by each of the four shock absorbers D interposed between each wheel W and the vehicle body B.

[0045] In addition, the target damping force calculation unit 3b multiplies the angular velocity in the roll direction of the vehicle body B at the center of gravity position of the vehicle body B by the roll suppression gain to obtain a roll suppression force that suppresses the roll, and multiplies the angular velocity in the pitch direction by the pitch suppression gain to obtain a pitch suppression force that suppresses the pitch.

[0046] Furthermore, the target damping force calculation unit 3b adds the roll suppression force and pitch suppression force that should be output by each of the four shock absorbers D to the skyhook damping force of each wheel W of the vehicle body B to calculate a damping force for ride comfort based on ride comfort control aimed at improving ride comfort in the vehicle V.

[0047] In addition, the target damping force calculation unit 3b multiplies the longitudinal acceleration of the center of gravity position of the vehicle body B by the longitudinal acceleration gain to obtain a longitudinal attitude change suppression force aimed at suppressing nose dive and squat of the vehicle body B during sudden acceleration or sudden braking, and multiplies the lateral acceleration of the center of gravity position of the vehicle body B by the lateral acceleration gain to obtain a lateral attitude change suppression force aimed at suppressing roll of the vehicle body B during cornering, and adds the longitudinal attitude change suppression force and lateral attitude change suppression force to be output by each of the four shock absorbers D to obtain a damping force for driving performance based on driving performance improvement control aimed at stabilizing the attitude of the vehicle body B of the vehicle V.

[0048] Then, the target damping force calculation unit 3b performs a high select process to select the larger absolute value of the ride comfort damping force value and the driving performance damping force value, and calculates the larger absolute value as the composite damping force. Note that, in calculating the composite damping force, the target damping force calculation unit 3b may add the ride comfort damping force and the driving performance damping force in a predetermined distribution. For example, the target damping force calculation unit 3b may calculate the composite damping force by adding together the value obtained by multiplying the ride comfort damping force by the ride comfort distribution gain and the value obtained by multiplying the driving performance damping force by the driving performance distribution gain, using a ride comfort control gain that determines the distribution of the ride comfort damping force based on the ride comfort control and a driving performance control gain that determines the distribution of the driving performance damping force based on the driving performance improvement control, each of which takes a value between 0 and 1.

[0049] Finally, the target damping force calculation unit 3b multiplies the composite damping force by a speed gain proportional to the traveling speed of the vehicle V to calculate the target damping force to be generated by the four shock absorbers D. The speed gain is calculated by multiplying the speed of the vehicle V by a speed sensitivity coefficient, and the speed gain increases in proportion to the traveling speed. The damping force control device 1 obtains the speed of the vehicle V from the mobile terminal 30. As described above, the mobile terminal 30 is equipped with a GPS receiver 30g, which detects the mobile terminal 30's own position information at a predetermined sampling period. The calculation processing unit 30f calculates the travel distance from the current position information and the position information obtained at the previous sampling period, and divides the calculated travel distance by the sampling period to calculate the traveling speed of the mobile terminal 30. The mobile terminal 30 performs wireless communication according to the above-mentioned standard, and therefore can only communicate with the damping force control device 1 over short distances. Therefore, when the mobile terminal 30 is traveling together with the vehicle V, it can transmit the speed information of the vehicle V to the damping force control device 1 via wireless communication. As described above, when the mobile terminal 30 and the damping force control device 1 are capable of wireless communication, the mobile terminal 30 continuously transmits speed information of the vehicle V to the damping force control device 1. When the damping force control device 1 receives an input of the speed of the vehicle V from the mobile terminal 30, it multiplies the speed by a speed sensitivity coefficient to calculate a speed gain, and multiplies the speed gain by the composite damping force to calculate a target damping force. Therefore, the damping force control device 1 of this embodiment can obtain the speed information of the vehicle V and calculate a target damping force appropriate for the speed, even without being connected to the CAN bus of the vehicle V. Note that, because speed changes of the vehicle V are sufficiently slower than changes in acceleration, etc. detected by the sensor unit 2, obtaining the speed information of the vehicle V from the mobile terminal 30 in the damping force control device 1 and using it to control the target damping force does not adversely affect the control of the damping force. On the other hand, the damping force control device 1 is equipped with the sensor unit 2, and can obtain the acceleration and angular velocity of the vehicle body B at a short sampling period to control the shock absorber D with good responsiveness. The damping force control device 1 may obtain only the position information from the mobile terminal 30 at a fixed period, calculate the speed of the vehicle V, and use the obtained speed to obtain the speed gain.

[0050] As described above, the target damping force calculation unit 3b in the control unit 3 acquires position information from the mobile terminal 30 and calculates the speed of the vehicle V, but if position information cannot be obtained from the mobile terminal 30, the target damping force may be calculated by calculating the speed from the acceleration detected by the sensor unit 2 and treating this as the speed of the vehicle V. Furthermore, if position information can be acquired from the mobile terminal 30 but the position information from the mobile terminal 30 is interrupted, such as when the vehicle V is traveling through a tunnel and the GPS receiver 30g cannot receive signals from a satellite, the target damping force calculation unit 3b in the control unit 3 may calculate the speed from the acceleration detected by the sensor unit 2 and treating this as the speed of the vehicle V to calculate the target damping force.

[0051] The target damping forces of the four shock absorbers D thus obtained are input to a current control unit 16 that controls the current supplied from the control unit 3 to the damping force adjusting unit 15 of each shock absorber D. The current control unit 16 supplies current to the solenoid 15c so that the damping force generated by the shock absorber D matches the target damping force.

[0052] In this embodiment, as shown in Fig. 3, the current control unit 16 includes a control calculation unit 16a that generates a current command for controlling the damping force adjusting unit 15, and a drive circuit 16b that supplies current to the solenoid 15c in accordance with the current command generated by the control calculation unit 16a, as shown in Fig. 4. Four drive circuits 16b are provided corresponding to the damping force adjusting units 15 of the four shock absorbers D. The current control unit 16 receives power supply through a power supply line connected to a battery (not shown) of the vehicle V.

[0053] Control calculation unit 16a calculates a target current based on a control command indicating a target damping force obtained from control unit 3. Specifically, control calculation unit 16a includes a current command calculation unit 16a1 that generates a current command indicating the amount of current to be applied to solenoid 15c of damping force adjustment unit 15 based on the target damping force indicated by the control command, and a PWM signal generation unit 16a2 that outputs a PWM signal to drive circuit 16b upon receiving the current command from current command calculation unit 16a1.

[0054] The current command calculation unit 16a1 stores in advance a map that indicates the relationship between the damping force generated by the shock absorber D and the amount of current supplied to the solenoid 15c of the damping force adjustment unit 15, and calculates the amount of current to be supplied to the solenoid 15c of the damping force adjustment unit 15 by map calculation from the target damping force input from the control unit 3. Note that the current command calculation unit 16a1 calculates the amount of current using the map, but if the relationship between the target damping force and the amount of current can be expressed as a function, the current amount may also be calculated using the function. In this way, the current command calculation unit 16a1 generates a current command that indicates the calculated amount of current.

[0055] The PWM signal generating unit 16a2 calculates the deviation between the current command calculated by the current command calculating unit 16a1 and the actual amount of current supplied to the solenoid 15c, performs PI compensation or PID compensation on the deviation to calculate a target current, and outputs a PWM signal for causing the drive circuit 16b to supply current to the solenoid 15c of the damping force adjusting unit 15 in accordance with the target current. In other words, the PWM signal generating unit 16a2 controls the damping force adjusting unit 15 by current feedback control. The PWM signal generating unit 16a2 obtains information on the current flowing through the solenoid 15c from a current sensor provided in the drive circuit 16b. The drive circuit 16b is connected to the solenoid 15c in the damping force adjustment unit 15 via wiring 17, and in order to adjust the amount of current supplied to the solenoid 15c, it is equipped with a switching element (not shown in detail) that can connect and disconnect the solenoid 15c to a power source not shown, and turns the switching element on and off at a duty ratio indicated by the PWM signal received from the PWM signal generation unit 16a2, thereby adjusting the amount of current to the solenoid 15c according to the target current.

[0056] The configuration of the current control unit 16 is just one example, and the current control unit 16 may be configured to supply current to the damping force adjustment unit 15 so as to generate a damping force in the shock absorber D in accordance with the target damping force indicated by the control command output by the control unit 3.

[0057] As described above, the target damping force calculation unit 3b in the control unit 3 uses various parameters, such as the skyhook damping coefficient, roll suppression gain, pitch suppression gain, longitudinal acceleration gain, lateral acceleration gain, and speed sensitivity coefficient, to determine the target damping force. As such, the parameters are set in advance and used for control, and are used to calculate the target damping force. In this embodiment, the damping force control device 1 executes ride comfort control aimed at improving ride comfort and driving performance improvement control aimed at improving driving performance, and the parameters used for these controls can be set using the mobile terminal 30.

[0058] Furthermore, when the damping force control device 1 does not perform the above control and causes the shock absorber D to function as a passive damper that generates a predetermined damping force in response to the extension / contraction speed, the damping force control device 1 allows the damping coefficient of the shock absorber D to be set as a parameter using the mobile terminal 30. When the damping force control device 1 causes the shock absorber D to function as a passive damper, the control unit 3 provides a fixed current command corresponding to the damping coefficient to the current control unit 16 so that the shock absorber D generates a damping force with the predetermined damping coefficient.

[0059] When the parameter setting unit 3c receives the parameter setting information from the mobile terminal 30, it changes the parameter values ​​used for calculation processing by the target damping force calculation unit 3b in the control unit 3 of this embodiment to values ​​according to the setting information. Specific parameter settings will be described later.

[0060] Although not shown as hardware, the control unit 3 and the control calculation unit 16a in the current control unit 16 include a CPU (Central Processing Unit), a memory, an interface, and a bus that connects these devices so that they can communicate with each other. Therefore, the damping force control device 1 is capable of two-way communication with a mobile terminal 30 outside the damping force control device 1 via the communication unit 5, and is also capable of supplying current from the drive circuit 16b to the damping force adjustment unit 15.

[0061] The CPU executes the operating system and other programs to realize the arithmetic processing of each unit in the control unit 3 of the damping force control device 1, namely, the acceleration calculation unit 3a, the target damping force calculation unit 3b, the parameter setting unit 3c, and the information collection unit 3d, as well as the arithmetic processing of the control calculation unit 16a of the current control unit 16, and controls the communication unit 5. In addition to ROM (Read Only Memory), the memory includes RAM (Random Access Memory) and flash memory that provide storage areas necessary for the CPU's arithmetic processing, and the programs used for the CPU's arithmetic processing are stored in the ROM. Note that the programs used for the CPU's arithmetic processing may be stored in a storage device other than the memory.

[0062] The damping force control device 1 configured as described above operates by receiving power supply from a battery (not shown) in the vehicle V, and is started when the ignition switch is turned on, starting the process of controlling the damping force of the shock absorber D.

[0063] Next, we will explain the control of the damping force control device 1 by the mobile terminal 30. When a setting application program for setting parameters of the damping force control device 1 is started on the mobile terminal 30, the arithmetic processing device 30f executes the setting application program, and the mobile terminal 30 displays a vehicle model registration button, an initial setting button, and a parameter setting button on the touch panel 30c as an initial screen, as shown in Fig. 6.

[0064] When the user taps the vehicle model registration button, processing for vehicle model registration is executed in both the mobile terminal 30 and the damping force control device 1. In the vehicle model registration processing, the vehicle model of the vehicle V in which the damping force control device 1 is used is set. When the user taps the initial setting button, processing for calculating the rotation matrix for correcting the installation attitude of the sensor unit 2 by calibration of the sensor unit 2 and the correction coefficient for correcting the deviation between the installation position of the sensor unit 2 and the center of gravity position of the vehicle body B is executed in both the mobile terminal 30 and the damping force control device 1. The initial setting processing is processing for calculating the rotation matrix required for the calculation processing of the acceleration calculation unit 3a in order to correct the three-axial angular velocities and three-axial accelerations detected by the sensor unit 2 into three-axial angular velocities and three-axial accelerations at the center of gravity position of the vehicle body B.

[0065] When the user taps the parameter setting button, a parameter setting process is executed in both the mobile terminal 30 and the damping force control device 1. The parameter setting process is a process in which the user operates the mobile terminal 30 to set parameters required for the calculation process by the target damping force calculation unit 3b to determine the target damping force. When the user taps the vibration data download button, a process is executed in which the vibration data file stored in the damping force control device 1 is transmitted from the communication unit 5, and the vibration data file is received by the mobile terminal 30 and saved in a storage device within the mobile terminal 30. The vibration data download process is a process in which the damping force control device 1 transmits a file compiling the vibration data that it sequentially generated and stored while the vehicle was traveling to the mobile terminal 30, and the mobile terminal 30 receives the file.

[0066] First, vehicle model registration will be described. When the user taps the vehicle model registration button, the mobile terminal 30 displays a manufacturer selection field and a vehicle model selection field for the vehicle V on the touch panel 30c. When the user taps the manufacturer selection field, a pull-down menu is displayed, displaying a list of manufacturers and allowing the user to select a manufacturer using the pull-down menu. After the user selects a manufacturer, the user taps the vehicle model selection field, displaying a pull-down menu, displaying a list of vehicle models manufactured by the selected manufacturer and allowing the user to select a vehicle model using the pull-down menu. Note that the mobile terminal 30 may allow the user to specify the manufacturer and vehicle model by entering characters in the manufacturer input field and the vehicle model field. After selecting the manufacturer and vehicle model or specifying the manufacturer and vehicle model, the user taps the registration button displayed on the touch panel 30c, ending the vehicle model registration process, and the mobile terminal 30 stores the vehicle model registration information. The setting application program incorporates data tables containing the dimensions, center of gravity position, vehicle weight, etc. of the vehicle body B for each vehicle model. The mobile terminal 30 can refer to these data tables to find data compatible with the registered vehicle model when performing the sensor position setting process and parameter setting process described below.

[0067] Next, the initial setting will be described. The initial setting is performed by the user tapping an initial setting button that is displayed after starting an application program for setting parameters on the mobile terminal 30. When performing the initial setting, the housing 20 that houses the sensor unit 2 of the damping force control device 1 is installed inside the passenger compartment of the vehicle body B, using the front-rear, left-right, and up-down directions displayed on the housing 20 as a guide. When the housing 20 is installed on the vehicle body B in alignment with the front-rear, left-right, and up-down directions relative to the vehicle body B, a rotation matrix for correcting the acceleration detected by the sensor unit 2 to the acceleration at a predetermined position on the vehicle body B can be obtained with high accuracy.

[0068] The rotation matrix is ​​a matrix for converting the three-axial acceleration detected by the sensor unit 2 into three-axial acceleration at the center of gravity, which is a predetermined position of the vehicle body B. Each component of the rotation matrix can be found from the pitch angle, roll angle, and yaw angle of the three detection axes of the sensor unit 2 relative to the up / down, left / right, front / rear, and rear axes of the vehicle V. By using the rotation matrix, the acceleration calculation unit 3a can accurately find the three accelerations at the center of gravity of the vehicle body B from the three-axial acceleration detected by the sensor unit 2 at the position where the sensor unit 2 is installed.

[0069] In the initial setting, the sensor unit 2 is calibrated by performing a process to correct any deviation in the mounting posture of the sensor unit 2 on the vehicle body B and a process to correct the deviation so that the angular velocity and acceleration of the center of gravity position can be detected even if the installation position of the sensor unit 2 on the vehicle body B is deviated from the center of gravity position.

[0070] When the user selects the initial setting, the mobile terminal 30 displays a sensor attitude setting button and a sensor position setting button on the touch panel 30c. When the user taps the sensor attitude setting button, a sensor attitude setting command is transmitted from the mobile terminal 30 to the damping force control device 1, and the sensor attitude setting process is executed.

[0071] When the sensor attitude setting process is started, as shown in FIG. 7, the mobile terminal 30 outputs a voice or displays a message on the touch panel 30c, or does both, to prompt the user to stop the vehicle V on a level road surface (step S101), and displays a confirmation button on the touch panel 30c to confirm that the vehicle V is stopped on a level road surface.

[0072] It is determined whether the user touches the confirmation button for a predetermined time or more (step S102). If the user does not tap the confirmation button for a predetermined time or more, the sensor orientation setting process ends (step S103).

[0073] On the other hand, when the user confirms that the vehicle V is parked on a level road surface and taps the confirmation button, the damping force control device 1 determines which way the acceleration detection axis of the sensor unit 2 faces relative to the vehicle body B, grasps the mounting attitude of the sensor unit 2 on the vehicle body B, and calculates the roll direction deviation and pitch direction deviation of the detection axis (step S104). Regarding whether the vehicle V is parked on a level road surface, the mobile terminal 30 is equipped with the inertial measurement unit 30b and can detect whether the mobile terminal 30 itself is level and stationary. Therefore, if the mobile terminal 30 is placed on a flat place parallel to the road surface inside the vehicle cabin and maintains a level and stationary state for a certain period of time or more, the mobile terminal 30 may determine that the vehicle V is parked on a level road surface and cause the damping force control device 1 to execute the processing of step S104.

[0074] When vehicle body B is parked on a horizontal road surface, only gravitational acceleration acts on vehicle body B, and therefore the combination of the three accelerations detected by sensor unit 2 is equal to the gravitational acceleration. Therefore, from the three-axis acceleration detected by sensor unit 2, it is possible to determine the deviation between the longitudinal detection axis and the actual longitudinal direction of vehicle body B, and the deviation between the lateral detection axis and the actual lateral direction of vehicle body B, and these deviations can be determined as roll angle and pitch angle deviations from the correct attitude of sensor unit 2.

[0075] Let the roll angle be φk, the pitch angle be θk, the acceleration in the longitudinal direction detected by the sensor unit 2 be αkx, the acceleration in the lateral direction be αky, and the acceleration in the vertical direction be αkz. The roll angle φk and the pitch angle θk can be calculated by calculating the following equation (1). The calculated roll angle φk and pitch angle θk indicate the degree of deviation in the roll direction, which is the direction of rotation around an axis about the longitudinal direction of the vehicle body B, and the pitch direction, which is the direction of rotation around an axis about the lateral direction of the vehicle body B, from the posture in which the three detection axes of the sensor unit 2 are correctly oriented relative to the longitudinal, lateral, and vertical directions of the vehicle body B. The calculations to calculate the roll angle φk and the pitch angle θk may be performed by the mobile terminal 30 or by the control unit 3 of the damping force control device 1.

[0076]

number

[0077] Simply calculating the roll angle φk and pitch angle θk in this manner does not reveal the extent of the deviation of the sensor unit 2 in the yaw direction around an axis that is the vertical direction of the vehicle body B. Therefore, after calculating the roll angle φk and pitch angle θk, the mobile terminal 30 outputs a voice message, displays a message on the touch panel 30c, or performs both, to instruct the user to drive the vehicle V straight for a certain period of time (step S105). It is determined whether the user, prompted by the instruction from the mobile terminal 30, has driven the vehicle V straight for a certain period of time or more (step S106). If the vehicle V has not driven straight for a certain period of time or more, the sensor attitude setting process is terminated (step S107). If the vehicle V has driven straight for a certain period of time or more, the damping force control device 1 determines the degree of deviation of the attitude of the sensor unit 2 from the longitudinal direction of the vehicle body B. This deviation can be calculated as a yaw angle ωk (step S108). The certain period of time for which the vehicle V is driven can be determined arbitrarily.

[0078] In this way, when the vehicle V travels straight on a horizontal road surface, the only thing acting on the vehicle body B is the acceleration of gravity and the acceleration in the longitudinal direction acting on the vehicle body B due to acceleration and deceleration while traveling. Therefore, the resultant force of the accelerations detected by the sensor unit 2 is the acceleration of gravity and the acceleration in the longitudinal direction during acceleration and deceleration. Therefore, by subtracting the resultant force of the accelerations of the three axes of the sensor unit 2 when only the acceleration of gravity is detected from the resultant force, the damping force control device 1 can determine the longitudinal direction of the vehicle body B. If the longitudinal direction of the vehicle body B is known in this way, it can be determined by how much angle the attitude of the sensor unit 2 deviates from the longitudinal direction of the vehicle body B. As described above, this deviation can be calculated as the yaw angle ωk. In this process, when the vehicle V travels straight, the vehicle V may travel either forward or backward.

[0079] By the above procedure, the roll angle φk, pitch angle θk, and yaw angle ωk can be calculated as errors between the attitude of the sensor unit 2 and the attitude when it is correctly attached in the front-rear, rear-rear, left-right, and up-down directions of the vehicle body B, and therefore a rotation matrix can be calculated for calculating the accelerations in the front-rear, rear-rear, left-right, and up-down directions of the vehicle body B and the angular velocities in the yaw, roll, and pitch directions, regardless of the attitude of the sensor unit 2. Therefore, the damping force control device 1 calculates the rotation matrix required to correct the attitude of the sensor unit 2 from the roll angle φk, pitch angle θk, and yaw angle ωk (step S109). Note that the mobile terminal 30, rather than the damping force control device 1, may calculate the roll angle φk, pitch angle θk, yaw angle ωk, and rotation matrix.

[0080] Once the rotation matrix required for correction has been calculated, the mobile terminal 30 outputs a voice message or displays a message on the touch panel 30c indicating that the sensor orientation setting process has been completed, or performs both (step S110), and then terminates the sensor orientation setting process and displays an initial screen on the touch panel 30c on which the initial settings, etc., can be selected.

[0081] Next, the sensor position setting will be described. When the user taps the sensor position setting button, a sensor position setting process is executed as shown in FIG. 8. In the sensor position setting process, the mobile terminal 30 displays a rough plan view of the vehicle body B on the touch panel 30c as shown in FIG. 9 (step S201), and prompts the user to input the installation position of the housing 20 by voice prompting the user to tap the installation position of the housing 20, or by displaying a message on the touch panel 30c, or by both. The touch panel 30c displaying the plan view in this manner functions as a position input unit for inputting the installation position of the sensor unit 2, and the user can input the installation position of the sensor unit 2 by tapping the installation position of the sensor unit 2 on the plan view displayed on the touch panel 30c. In the damping force control device 1 of this embodiment, the sensor unit 2 is housed in the housing 20, so the user can input the installation position of the sensor unit 2 by tapping the installation position of the housing 20 on the position input unit.

[0082] The mobile terminal 30 determines whether the installation position of the housing 20 has been input by the user (step S202), and if the installation position of the housing 20 has been input, it refers to a data table to retrieve data on the dimensions and center of gravity position of the vehicle body B that is compatible with the registered vehicle model, and calculates the geometric error of the installation position, which is the difference between the center of gravity position of the vehicle body B and the installation position of the housing 20 input by the user (step S203).If the installation position of the housing 20 has not been input by the user, the mobile terminal 30 ends the sensor position setting process (step S204).

[0083] In the processing of step S203, the position of the center of gravity of the vehicle body B may be set as the position of the center of gravity of a general vehicle V, and the geometric error between the installation position of the housing 20 input by the user and the installation position of the center of gravity may be calculated. Since the sensor unit 2 detects angular velocity and acceleration, if the geometric error between the position of the center of gravity of the vehicle body B and the installation position of the sensor unit 2 can be grasped, correction coefficients can be calculated to obtain the angular velocities and angular accelerations at the position of the center of gravity of the vehicle body B from the angular velocities and angular accelerations detected by the sensor unit 2.

[0084] In this way, when the user inputs the installation position of the housing 20 on the vehicle body B and determines the geometric error between the installation position when the vehicle V is viewed from directly above and the position of the center of gravity of the vehicle body B, the damping force control device 1 receives the input of the geometric error from the mobile terminal 30, corrects the three-axial angular velocities and accelerations detected by the sensor unit 2 based on the geometric error between the installation position and the position of the center of gravity, and determines correction coefficients for determining the three-axial angular velocities and accelerations of the position of the center of gravity of the vehicle body B (step S205), and terminates the sensor position setting process (step S206). Note that the mobile terminal 30 may determine the correction coefficients and transmit information about the correction coefficients to the damping force control device 1. Alternatively, the damping force control device 1 may determine the geometric error.

[0085] Furthermore, the sensor position setting process may be different from the above process. Specifically, with the mobile terminal 30 installed at the center of gravity of the vehicle body B, the vehicle body B is vibrated to cause the inertial measurement unit 30b of the mobile terminal 30 to detect the angular velocity and acceleration, and the sensor unit 2 to detect the angular velocity and acceleration, and the error between the accelerations is calculated. Note that the center of gravity of the vehicle body B can be determined by the mobile terminal 30 from the registered vehicle model data. For example, the touch panel 30c of the mobile terminal 30 can display the location of the center of gravity in the cabin of the vehicle body B, and the user can install the mobile terminal 30 while relying on the display. If the mobile terminal 30 is installed at the center of gravity of the vehicle body B, vibrations can be applied to the vehicle body B, and the three-axis angular velocities and three-axis accelerations detected by the inertial measurement unit 30b in the mobile terminal 30 will match the three-axis accelerations and three-axis accelerations at the center of gravity of the vehicle body B. Therefore, the error between the three-axis angular velocities and three-axis accelerations detected by the sensor unit 2 when the vibrations are applied to the vehicle body B and the three-axis angular velocities and three-axis accelerations detected by the mobile terminal 30 can be determined, and from this error, a correction coefficient to be multiplied by the three-axis angular velocities and three-axis accelerations detected by the sensor unit 2 can be determined to match the three-axis angular velocities and three-axis accelerations at the center of gravity of the vehicle body B.

[0086] Furthermore, if the center of gravity of vehicle body B is located within the vehicle interior space and mobile terminal 30 cannot be installed, the location within the vehicle interior where mobile terminal 30 should be installed can be displayed on touch panel 30c of mobile terminal 30, prompting the user to install mobile terminal 30 in that location. In this case, the installation location of mobile terminal 30 is misaligned with the center of gravity of vehicle body B, but since the geometric error between the location where mobile terminal 30 should be installed and the center of gravity of vehicle body B can be known in advance, the angular velocity and acceleration detected by inertial measurement unit 30b of mobile terminal 30 can be corrected to the angular velocity and acceleration of the center of gravity of vehicle body B based on the geometric error.

[0087] Then, the damping force control device 1 calculates a correction coefficient for obtaining the angular velocity and acceleration at the center of gravity position from the errors in the angular velocity and acceleration. The calculation process for the coefficient may be performed by the mobile terminal 30. Once the correction coefficient for correction is calculated by executing the sensor position setting process in this way, the process ends.

[0088] Next, the parameter setting will be described. When the user taps the parameter setting button, the mobile terminal 30 displays an adjustment section, which is an operation screen for setting parameters, on the touch panel 30c, as shown in FIG.

[0089] The operation screen includes an operation area Z1 for setting the magnitude of the damping force, an operation area Z2 for setting parameters for ride comfort control and driving performance improvement control, an operation area Z3 for setting a speed sensitivity coefficient to be multiplied by the driving speed of the vehicle V, and an operation area Z4 for sending and saving all of the settings made by the user in the operation areas Z1, Z2, and Z3 to the damping force control device 1. If the operation screen does not fit within the touch panel 30c, the display range of the operation screen can be scrolled or the screen can be switched for each of the operation areas Z1, Z2, Z3, and Z4 so that the operation area that the user wants to operate is displayed by an operation such as sliding or swiping by the user.

[0090] The operation area Z1 is an area where an operation for setting the magnitude of the damping force is performed. Specifically, as shown in Fig. 10 , a bar graph and numerical values ​​indicating the magnitude of the damping force of the shock absorber D arranged on the left front side of the vehicle V are displayed in the upper left of the operation area Z1, a bar graph and numerical values ​​indicating the magnitude of the damping force of the shock absorber D arranged on the right front side of the vehicle V are displayed in the upper right of the operation area Z1, a bar graph and numerical values ​​indicating the magnitude of the damping force of the shock absorber D arranged on the left rear side of the vehicle V are displayed in the lower left of the operation area Z1, and a bar graph and numerical values ​​indicating the magnitude of the damping force of the shock absorber D arranged on the right rear side of the vehicle V are displayed in the upper center of the operation area Z1, as parameters for setting the damping coefficients of the left and right front shock absorbers D, and a down button 101 for increasing the damping coefficient and a down button 102 for decreasing the damping coefficient and a down button 103 for decreasing the damping coefficient are displayed in the lower center of the operation area Z1, as parameters for setting the damping coefficients of the left and right rear shock absorbers D.

[0091] When the user touches the up button 100 for setting the damping coefficients of the left and right front shock absorbers D, which is displayed in the upper center of the operation area Z1, the value of the damping coefficient increases according to the duration of the touch, and accordingly, the two bar graphs at the upper left and upper right of the operation area Z1 extend upward in unison, and the numerical value below the bar graph also increases. When the user touches the down button 101 for setting the damping coefficients of the left and right front shock absorbers D, which is displayed in the upper center of the operation area Z1, the value of the damping coefficient decreases according to the duration of the touch, and accordingly, the two bar graphs at the upper left and upper right of the operation area Z1 shrink downward in unison, and the numerical value below the bar graph also decreases. Similarly to setting the damping coefficient of the front shock absorber D, the user can also set the magnitude of the damping coefficient of the rear shock absorber D by operating the up button 102 and down button 103.

[0092] The value of the damping coefficient as a parameter can only be set by the user within a predetermined range from minimum to maximum, and in the display in operation area Z1, the minimum damping coefficient is displayed as 0, and the maximum damping coefficient is displayed as 100. The minimum and maximum damping coefficient values ​​are predetermined, and the damping coefficient is set to a corresponding value in the range from minimum to maximum depending on the value selected by the user. Therefore, for example, if the value set by the user is 50, the damping coefficient is set to the midpoint between the minimum and maximum values.

[0093] The reason for limiting the range in which the user can set the damping coefficient is to prevent the damping force from becoming too small or too large, which would result in a poor ride and driving performance. Also, the damping coefficients of the shock absorbers D arranged on the left and right sides of the vehicle V are set synchronously, rather than being set separately, in order to prevent variations in driving performance during cornering, etc., which would impair ride comfort. However, up and down buttons for setting the damping coefficients corresponding to the four shock absorbers D may be provided in the operation area Z1 so that the damping coefficients of the left and right shock absorbers D can be set independently. Furthermore, for setting the damping coefficient, instead of or in addition to the up and down buttons, an input field for directly inputting a numerical value may be provided.

[0094] The operation area Z2 is an area where an operation is performed to set parameters for the ride comfort control and the driving performance improvement control. Specifically, as shown in Fig. 10, a switch 201 for selecting whether or not to cause the damping force control device 1 to execute the ride comfort control and the driving performance improvement control is displayed in the upper left of the operation area Z2, a first slider bar 202 for setting the intensity of the ride comfort control is displayed below the switch 201, and a second slider bar 203 for setting the intensity of the driving performance improvement control is displayed below the first slider bar 202.

[0095] The switch 201 is a switch that switches the control on and off. When the switch 201 is switched on by a user operation and a command to enable the control is sent from the mobile terminal 30 to the damping force control device 1, the damping force control device 1 enables the control and executes a process of calculating the damping force based on the ride comfort control and the damping force based on the driving performance improvement control to determine the target damping force.

[0096] On the other hand, when the user switches switch 201 off and sends a command to the damping force control device 1 from the mobile terminal 30 to disable control, the damping force control device 1 disables the control and does not execute the process of calculating the damping force based on the ride comfort control and the damping force based on the driving performance improvement control to determine the target damping force, but executes the process of determining the target damping force based on the damping coefficient set in the operation area Z1.

[0097] The first slider bar 202 displays a first slider 202a that the user can operate left and right in FIG. 10 . When the user touches and moves the first slider 202a left and right, the ride comfort control intensity changes between 0 and 100. The ride comfort control intensity is displayed as a numerical value on the left side of the first slider bar 202. Thus, the user can set the ride comfort control intensity to their liking by operating the first slider 202a of the first slider bar 202. When the ride comfort control intensity is set to 0, the skyhook damping coefficient, roll suppression gain, and pitch suppression gain, which are parameters used for ride comfort control, are set to their minimum values. When the ride comfort control intensity is set to 100, the skyhook damping coefficient, roll suppression gain, and pitch suppression gain are set to their maximum values. When the ride comfort control intensity is set to the median value of 50, the skyhook damping coefficient, roll suppression gain, and pitch suppression gain are set to their median values ​​between their respective minimum and maximum values.

[0098] In this way, when the user operates the first slider 202a of the first slider bar 202, the values ​​of the skyhook damping coefficient, roll suppression gain, and pitch suppression gain, which are parameters used for ride comfort control, change between minimum and maximum values ​​according to the value set by the first slider 202a. Note that when setting the strength to 0 by operating the first slider 202a, the values ​​of the skyhook damping coefficient, roll suppression gain, and pitch suppression gain may be set to 0 to set the ride comfort damping force based on the ride comfort control to 0. However, if this is done, when the strength of the driving performance improvement damping force based on the driving performance improvement control is also set to 0, and the longitudinal acceleration gain and lateral acceleration gain, which are parameters used for the driving performance improvement control, are set to 0, the target damping force becomes 0, the damping force becomes extremely low, and ride comfort deteriorates, which may result in a deterioration in driving performance. For this reason, even when the ride comfort control strength is set to 0, the values ​​of the skyhook damping coefficient, roll suppression gain, and pitch suppression gain are set to minimum values ​​above 0 that do not impair ride comfort. Furthermore, with regard to the maximum values ​​of the skyhook damping coefficient, roll suppression gain, and pitch suppression gain, if the values ​​of these gains become too large, the target damping force will become too high, which may actually worsen the ride comfort, so the maximum values ​​are set in advance so as not to worsen the ride comfort.

[0099] The second slider bar 203 displays a second slider 203a that the user can operate left and right in FIG. 10 . When the user touches and moves the second slider 203a left and right, the intensity of the driving performance improvement control changes between 0 and 100. The intensity of the driving performance improvement control is displayed as a numerical value on the left side of the second slider bar 203. Thus, the user can set the intensity of the driving performance improvement control to their liking by operating the second slider 203a of the second slider bar 203. When the intensity of the driving performance improvement control is set to 0, the longitudinal acceleration gain and the lateral acceleration gain, which are parameters used for the driving performance improvement control, are set to their minimum values. When the intensity of the driving performance improvement control is set to 100, the longitudinal acceleration gain and the lateral acceleration gain are set to their maximum values. When the intensity of the driving performance improvement control is set to the median value of 50, the longitudinal acceleration gain and the lateral acceleration gain are set to their median values ​​between their respective minimum and maximum values.

[0100] In this way, by the user operating the second slider 203a on the second slider bar 203, the values ​​of the longitudinal acceleration gain and lateral acceleration gain, which are parameters used for the driving performance improvement control, change between minimum and maximum values ​​according to the value set by the second slider 203a. Note that if the values ​​of the skyhook damping coefficient, roll suppression gain, and pitch suppression gain, which are parameters for the ride comfort improvement control, do not become 0 when set to their minimum values, when the strength is set to 0 by operating the second slider 203a, the values ​​of the longitudinal acceleration gain and lateral acceleration gain may be set to 0 so that the ride comfort damping force based on the ride comfort control becomes 0.

[0101] On the other hand, when the values ​​of the skyhook damping coefficient, roll suppression gain, and pitch suppression gain in the parameters for ride comfort improvement control are set to 0 when they are at their minimum values, it is better to ensure that the values ​​of the longitudinal acceleration gain and lateral acceleration gain do not become 0 even when the strength is set to 0 by operating the second slider 203a, so that the target damping force does not become 0 and the damping force becomes extremely low, thereby preventing deterioration of driving performance.

[0102] Therefore, even if the intensity of the driving performance improvement control is set to 0, the values ​​of the longitudinal acceleration gain and the lateral acceleration gain are set to minimum values ​​that exceed 0 and do not impair driving performance. Note that, as for the maximum values ​​of the longitudinal acceleration gain and the lateral acceleration gain, if the values ​​of these gains become too large, the target damping force becomes too high, which may actually worsen driving performance, so the maximum values ​​are set in advance so as not to impair driving performance.

[0103] Operation area Z3 is an area where an operation is performed to set a speed sensitivity coefficient to be multiplied by the traveling speed of vehicle V. Specifically, as shown in Fig. 10, a switch 301 for selecting whether or not to generate a damping force dependent on speed is displayed in the upper left of operation area Z3, a slider bar 302 for setting the speed sensitivity coefficient is displayed below switch 301, and a graph 303 showing the characteristics of the damping force relative to the speed of vehicle V corresponding to the speed sensitivity coefficient selected with slider bar 302 is displayed.

[0104] The switch 301 is a switch that switches whether or not to make the damping force sensitive to the speed to generate a damping force that depends on the speed. When the switch 301 is turned on by a user operation and a command to enable speed-sensitive control is sent from the mobile terminal 30 to the damping force control device 1, the damping force control device 1 executes a process of multiplying the speed of the vehicle V by the speed sensitivity coefficient to obtain a speed gain, and then using the speed gain to obtain a target damping force.

[0105] On the other hand, when the user switches switch 301 off and a command to disable speed-sensitive control is sent from the mobile terminal 30 to the damping force control device 1, the damping force control device 1 determines the target damping force by setting the speed gain to 1 in the processing in the target damping force calculation unit 3b, or by not multiplying the speed gain by the composite damping force and using the composite damping force as is as the target damping force, thereby obtaining the target damping force. Also, when the user switches switch 301 off, the damping force control device 1 does not need the position information from the mobile terminal 30, so transmission of position information from the mobile terminal 30 to the damping force control device 1 may be stopped.

[0106] The slider bar 302 displays a speed sensitivity adjustment slider 302a that the user can operate left and right in FIG. 10 . When the user touches and moves the speed sensitivity adjustment slider 302a left and right, the value of the speed sensitivity coefficient changes between the minimum and maximum values. The speed sensitivity coefficient level is displayed to the left of the speed sensitivity adjustment slider 302a. When the user operates the speed sensitivity adjustment slider 302a, the level changes between 0, which corresponds to the minimum value of the speed sensitivity coefficient, and 100, which corresponds to the maximum value of the speed sensitivity coefficient. Thus, the user can set the sensitivity of the damping force to the speed to their liking by operating the speed sensitivity adjustment slider 302a on the slider bar 302. When the speed sensitivity coefficient level is set to 0, the speed sensitivity coefficient is set to the minimum value. On the other hand, when the speed sensitivity coefficient level is set to 100, the speed sensitivity coefficient is set to the maximum value.

[0107] In this way, when the user operates the speed sensitivity adjustment slider 302a on the slider bar 302, the value of the speed sensitivity coefficient changes between a minimum value and a maximum value according to the value set by the speed sensitivity adjustment slider 302a. As described above, the target damping force calculation unit 3b obtains a speed gain by multiplying the speed of the vehicle V by the speed sensitivity coefficient, and then obtains the target damping force by multiplying the speed gain by which the composite damping force is multiplied. Therefore, the speed sensitivity coefficient is a coefficient for obtaining the speed gain, and the value of the speed sensitivity coefficient takes a value greater than 0. Furthermore, the maximum and minimum values ​​of the speed sensitivity coefficient are set so that the target damping force does not become too small, thereby preventing the ride comfort of the vehicle from being deteriorated.

[0108] Graph 303 displays the characteristics of the damping force relative to the speed of vehicle V, corresponding to the level of the speed sensitivity coefficient set by the user by operating speed sensitivity adjustment slider 302a. Note that graph 303 shows by a dashed line the characteristics of the damping force relative to the speed of vehicle V when the speed sensitivity coefficient level is set to 50, allowing the user to recognize at a glance how much the characteristics set by the user deviate from the characteristics when the speed sensitivity coefficient level is set to 50 by operating speed sensitivity adjustment slider 302a.

[0109] The operation screen includes an operation area Z4 below each operation area Z1, Z2, and Z3, where the user can collectively transmit and save the settings made by the user in each operation area Z1, Z2, and Z3 to the damping force control device 1. A save button 401 and a send button 402 are displayed in the operation area Z4. When the user taps the save button 401, the mobile device 30 stores the setting information for each item made by the user in the operation areas Z1, Z2, and Z3 as a single setting file in the memory 30e. In this way, the memory 30e functions as a storage unit for storing parameter setting information in the mobile device 30. The mobile device 30 can store multiple setting files, and the user can select the setting file they want to use from the multiple saved setting files. When the user selects a setting file, the mobile device 30 loads the setting information in the selected setting file and reflects the parameter values ​​in the loaded setting information in the parameter values ​​of the adjustment units in the operation areas Z1, Z2, and Z3 on the parameter setting screen. When saving a setting file, the user may be allowed to give the setting file an arbitrary name. When a setting application program is started on the mobile terminal 30, the saved setting information for each item may be automatically read and reflected in each operation area Z1, Z2, and Z3 on the parameter setting screen.

[0110] As described above, the up buttons 100, 102 and the down buttons 101, 103 in the operation area Z1 displayed on the touch panel 30c of the mobile terminal 30, the first slider 202a and the second slider 203a in the operation area Z2, and the speed-sensitive adjustment slider 302a in the operation area Z3 function as adjustment units for setting parameters. In addition, the bar graph and numerical values ​​in the operation area Z1 displayed on the touch panel 30c of the mobile terminal 30, the numerical values ​​to the left of the first slider bar 202 and the second slider bar 203 in the operation area Z2, and the graph 303 in the operation area Z3 function as display units for displaying parameter setting information.

[0111] When the user taps the send button 402, the mobile terminal 30 executes a transfer process to transmit parameter setting information to the damping force control device 1 via the transceiver 30d. Specifically, when communication between the transceiver 30d and the damping force control device 1 is established, the mobile terminal 30 transmits setting information for each item currently in each of the operation areas Z1, Z2, and Z3 to the damping force control device 1 via wireless communication. More specifically, as shown in FIG. 11, when the user operates the send button 402, the mobile terminal 30 compiles the current setting information in each of the operation areas Z1, Z2, and Z3 into a single file (step S301) and executes a process to establish communication with the damping force control device 1 to transmit the file to the damping force control device 1 (step S302). The mobile terminal 30 waits for a response from the damping force control device 1 and determines whether or not there is a response (S303). If there is no response from the damping force control device 1 after a certain period of time has elapsed, the mobile terminal 30 terminates the process to establish a connection (step S304). In this case, after the process of establishing the connection is completed, the mobile terminal 30 displays a communication error on the touch panel 30c and ends the transmission process (step S305).

[0112] On the other hand, when communication with the damping force control device 1 is established, the mobile terminal 30 transmits a file of parameter setting information to the damping force control device 1 (step S306), and terminates the transmission process when the transmission is complete. When the damping force control device 1 receives the file of parameter setting information from the mobile terminal 30 via the communication unit 5 (step S307), the parameter setting unit 3c in the control unit 3 executes a process of overwriting each parameter used by the target damping force calculation unit 3b with a value specified by the setting information (S308). When the parameter setting unit 3c completes the process of overwriting the parameter values, the parameter setting process in the damping force control device 1 terminates.

[0113] When the mobile terminal 30 determines that the vehicle V is traveling based on the location information detected by the GPS receiver 30g, the damping force control device 1 may only receive parameter setting information when the user taps the send button and update the values ​​of each parameter to the values ​​set by the user according to the setting information received after the vehicle V has stopped, or may not receive parameter setting information even when the user taps the send button. Furthermore, when the mobile terminal 30 itself determines that the vehicle V is traveling based on the location information detected by the GPS receiver 30g, the damping force control device 1 may not transmit parameter setting information even when the user taps the send button, and may display on the touch panel 30c a message indicating that parameter setting is not possible while the vehicle V is traveling, or may not accept operation of the data send button while the vehicle V is traveling. If the values ​​of the parameters used to control the damping force in the damping force control device 1 change significantly while the vehicle V is traveling, the target damping force may change significantly while the vehicle V is traveling, which may result in a sudden change in ride comfort. Therefore, parameter setting may be restricted while the vehicle V is traveling.

[0114] Furthermore, as described above, the damping force control device 1 is configured to start up when the ignition switch is turned on, but it may receive power from the battery of the vehicle V regardless of whether the ignition switch is on or off, or if it has its own power source, it may go into a standby state in which it can perform wireless communication when the ignition switch is off, and start up when it receives a request to receive parameter setting information from the mobile terminal 30, receive a file of parameter setting information, and set the parameters.

[0115] As described above, the damping force control device 1 of this embodiment comprises a sensor unit 2 that detects vibrations at a predetermined position of the body B of the vehicle V, a control unit 3 that controls the damping force of a damping force adjustable shock absorber installed between the body B and the wheel W of the vehicle V based on vibration information detected by the sensor unit 2, and a communication unit 5 that can communicate wirelessly with a mobile terminal 30, and is configured to calibrate the sensor unit 2 based on instructions from the mobile terminal 30.

[0116] With the damping force control device 1 configured in this manner, the user can easily instruct calibration of the sensor unit 2 in the damping force control device 1 using a mobile terminal 30, including smart devices such as smartphones and tablet terminals that the user carries with them on a daily basis and is familiar with operating, without using a dedicated operating device.In addition, since the calibration can correct the vibration information detected by the sensor unit 2, the sensor unit 2 can be installed at any position on the vehicle body B, making installation on the vehicle V easy.

[0117] In addition, the damping force control system S of this embodiment includes a sensor unit 2 that detects vibrations at a predetermined position of the body B of the vehicle V, a control unit 3 that controls the damping force of a damping force adjustable shock absorber D provided between the body B of the vehicle V and the wheel W based on the vibration information detected by the sensor unit 2, a damping force control device 1 having a communication unit 5 capable of wireless communication, and a mobile terminal 30 that has an inertial measurement unit 30b and is capable of wireless communication with the damping force control device 1, and is configured to calibrate the sensor unit 2 based on the error between the vibration information detected by the sensor unit 2 and the vibration information detected by the mobile terminal 30.

[0118] According to the damping force control system S configured in this manner, the vibration information of the sensor unit 2 can be corrected so that vibration information at a predetermined position on the vehicle body B can be obtained using the mobile terminal 30, making the calibration process extremely easy, and since the sensor unit 2 can be installed at any position on the vehicle body B, it also becomes easy to install the damping force control device 1 on the vehicle V. Furthermore, not only can the mobile terminal 30 be used for calibration, eliminating the need for dedicated equipment, but also instructions can be given to the user from the mobile terminal 30 during the calibration process, so even a user with little knowledge of calibration can easily perform the calibration process.

[0119] In addition, the damping force control system S of this embodiment includes a sensor unit 2 that detects vibrations at a predetermined position on the body B of the vehicle V, a control unit 3 that controls the damping force of a damping force adjustable shock absorber D provided between the body B and the wheels W of the vehicle V based on vibration information detected by the sensor unit 2, a damping force control device 1 having a communication unit 5 capable of wireless communication, and a mobile terminal 30 that has a touch panel 30c and is capable of wireless communication with the damping force control device 1, and the mobile terminal 30 has a position input unit that is displayed on the touch panel 30c and that allows the installation position of the sensor unit 2 relative to the body B to be input, and is configured to calibrate the sensor unit 2 based on the installation position input using the position input unit.

[0120] According to the damping force control system S configured in this manner, the installation position of the sensor unit 2 relative to the vehicle body B can be input using the mobile terminal 30, and therefore the sensor unit 2 can be calibrated by understanding the geometric error between a predetermined value of the vehicle body B and the installation position of the sensor unit 2, making the calibration work extremely easy, and since the sensor unit 2 can be installed at any position on the vehicle body B, it also makes it easy to install the damping force control device 1 in the vehicle V. Furthermore, not only can the mobile terminal 30 be used for calibration, eliminating the need for dedicated equipment, but also since instructions can be given to the user from the mobile terminal 30 during the calibration work, so that even a user with little knowledge of calibration can easily perform the calibration work.

[0121] Furthermore, the damping force control system S of this embodiment is configured to calibrate the sensor unit 2 with the mobile terminal 30 installed at a predetermined position on the vehicle body B. According to the damping force control system S configured in this manner, the detection result of the inertial measurement unit 30b of the mobile terminal 30 can be used to easily and accurately calibrate the sensor unit 2.

[0122] Furthermore, the correction method for the sensor unit 2 of this embodiment is a correction method for the sensor unit 2 that calibrates the sensor unit 2 that detects three-axial accelerations in the forward / backward, left / right, and up / down directions and three-axial angular velocities in the pitch, roll, and yaw directions at a predetermined position on the body B of the vehicle V, and includes a procedure for calculating a rotation matrix that corrects the attitude of the sensor unit 2 with respect to the body B based on the detection results of the three-axial acceleration detected by the sensor unit 2 when the vehicle V is parked on a horizontal road surface and the detection results of the three-axial acceleration detected by the sensor unit 2 when the vehicle V is moving straight, and a procedure for calculating a correction coefficient that corrects the three-axial angular velocities and three-axial accelerations detected by the sensor unit 2 to the three-axial angular velocities and three-axial accelerations at the predetermined position based on the error between the three-axial angular velocities and three-axial accelerations detected by the mobile terminal 30 installed at the predetermined position and the three-axial angular velocities and three-axial accelerations detected by the sensor unit 2, or the geometric error between the installation position of the sensor unit 2 with respect to the body and the predetermined position specified by the mobile terminal 30.

[0123] According to the correction method for the sensor unit 2 configured in this manner, correction is performed to align the acceleration detection axis of the sensor unit 2 with the front-to-back, left-to-right, and top-to-bottom directions of the vehicle body B, and correction is made for angular velocity and acceleration caused by geometric errors between the installation position of the sensor unit 2 and a predetermined position.Therefore, regardless of the installation position of the sensor unit 2, calibration of the sensor unit 2 can be easily performed using the mobile terminal 30, and installation of the damping force control device 1 in the vehicle V is also made easy, making it ideal for the damping force control device 1 and the damping force control system S.

[0124] Although the preferred embodiment of the present invention has been described in detail, modifications, variations and changes can be made thereto without departing from the scope of the appended claims. [Explanation of symbols]

[0125] 1···Damping force control device, 2···Sensor unit, 3···Control unit, 5···Communication unit, 20···Housing, 30···Mobile terminal, 30b···Inertial measurement unit, 30c···Touch panel, B···Vehicle body, D···Shock absorber, S···Damping force control system, V···Vehicle, W···Wheel

Claims

1. a sensor unit that detects vibrations at a predetermined position on the vehicle body; a control unit that controls a damping force of an adjustable damping force shock absorber that is provided between the vehicle body and the wheels of the vehicle based on the vibration information detected by the sensor unit; A communication unit capable of wirelessly communicating with a mobile terminal, Calibrating the sensor unit according to an instruction from the mobile terminal A damping force control device characterized by:

2. a damping force control device including a sensor unit that detects vibrations at a predetermined position of a vehicle body, a control unit that controls the damping force of an adjustable damping force shock absorber that is provided between the vehicle body and a wheel of the vehicle based on vibration information detected by the sensor unit, and a communication unit that is capable of wireless communication; a mobile terminal having an inertial measurement unit and capable of wireless communication with the damping force control device; The sensor unit is calibrated based on an error between vibration information detected by the sensor unit and vibration information detected by the mobile terminal. A damping force control system characterized by:

3. a damping force control device including a sensor unit that detects vibrations of a vehicle body, a control unit that controls the damping force of an adjustable damping force shock absorber that is provided between the vehicle body and a wheel of the vehicle based on vibration information detected by the sensor unit, and a communication unit that is capable of wireless communication; a mobile terminal having a touch panel and capable of wireless communication with the damping force control device; the mobile terminal has a position input unit that is displayed on the touch panel and allows input of an installation position of the sensor unit relative to the vehicle body; Calibrating the sensor unit based on the installation position input using the position input unit A damping force control system characterized by:

4. The sensor unit is calibrated with the mobile terminal installed at a predetermined position on the vehicle body.

3. The damping force control system according to claim 2.

5. A method for correcting a sensor unit that detects accelerations in three axes, i.e., front-rear, left-right, and up-down directions, and angular velocities in three axes, i.e., pitch, roll, and yaw directions, at a predetermined position on a vehicle body, comprising: a step of calculating a rotation matrix for correcting the attitude of the sensor unit relative to the vehicle body based on a detection result of three-axis acceleration detected by the sensor unit while the vehicle is parked on a horizontal road surface and a detection result of three-axis acceleration detected by the sensor unit while the vehicle is moving straight; and a procedure for calculating a correction coefficient for correcting the triaxial angular velocities and triaxial accelerations detected by the sensor unit to the triaxial angular velocities and triaxial accelerations at the predetermined position, based on an error between the triaxial angular velocities and triaxial accelerations detected by the portable terminal installed at the predetermined position and the triaxial angular velocities and triaxial accelerations detected by the sensor unit, or based on a geometric error between an installation position of the sensor unit with respect to the vehicle body specified by the portable terminal and the predetermined position. A method for correcting a sensor unit, comprising:

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