Vibration presentation device

Abstract

Provided is a vibration presentation device that can be retrofitted to a seat and is capable of presenting a vibration that can be perceived by a seated person.　The vibration presentation device includes: a cushion that can be positioned on a seat; an orientation detection unit that detects the orientation of the cushion; a degree-of-contact detection unit that detects the degree of contact between the cushion and the seated person sitting on the seat on which the cushion is positioned; a vibration generation unit that causes the cushion to vibrate; and a control unit that performs drive control of the vibration generation unit on the basis of the cushion orientation detected by the orientation detection unit and the degree of contact detected by the degree-of-contact detection unit.

Description

Vibration presentation device

[0001] The present disclosure relates to a vibration presentation device.

[0002] Conventionally, there has been a vehicle seat that is characterized by comprising a vibration generating means that is disposed in the seating portion of the seat and generates vibrations, a pressure detecting means that is disposed in the seating portion of the seat and detects pressure from a seated occupant, and a vibration control means that sets the vibration intensity of the vibration generating means based on the pressure detected by the pressure detecting means and controls the vibration generating means to generate vibrations of the set intensity (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2007-137387

[0004] However, conventional vehicle seats are fixed to the seat and cannot be retrofitted to the seat. Furthermore, if a retrofittable configuration were adopted, the way in which vibrations are transmitted to the seat occupant may differ depending on the installation state of the seat. Furthermore, if the way in which vibrations are transmitted to the occupant differs, it may become difficult to convey information to the occupant through vibrations. Similar problems may also occur in seats that are not installed in a moving body such as a vehicle.

[0005] Therefore, an object of the present invention is to provide a vibration presentation device that can be retrofitted to a seat and presents vibrations that can be perceived by the seated occupant.

[0006] A vibration presentation device according to an embodiment of the present disclosure includes a cushion that can be placed on a seat, a posture detection unit that detects the posture of the cushion, a contact degree detection unit that detects the degree of contact between an occupant sitting on the seat on which the cushion is placed and the cushion, a vibration generation unit that vibrates the cushion, and a control unit that controls the drive of the vibration generation unit based on the posture of the cushion detected by the posture detection unit and the degree of contact detected by the contact degree detection unit.

[0007] It is possible to provide a vibration presentation device that can be retrofitted to a seat of a moving body and that can present vibrations that can be perceived by a seated person.

[0008] 1 is a diagram illustrating an example of the configuration of a vibration presentation device of an embodiment; FIG. 2 is a diagram illustrating an example of a state in which a vibration presentation device of an embodiment is placed on a seat of a vehicle; FIG. 3 is a diagram illustrating an example of the details of the internal configuration of a vibration presentation device of an embodiment; FIG. 4 is a diagram illustrating an example of an arrangement of an acceleration sensor and a vibration device in a vibration presentation device of an embodiment, and an example of a vibration direction of the vibration device; FIG. 5 is a diagram illustrating an example of an arrangement of an acceleration sensor and a vibration device in a vibration presentation device of an embodiment, and an example of a vibration direction of the vibration device; FIG. 6 is a diagram illustrating an example of a state in which a vibration presentation device of an embodiment is placed on a seat; FIG. 7 is a diagram illustrating an example of a posture estimation result using an acceleration sensor and a gyro sensor; FIG. 8 is a diagram illustrating an example of a state in which a vibration presentation device of an embodiment is placed on a seat;

[0009] Hereinafter, an embodiment to which the vibration presentation device of the present disclosure is applied will be described.

[0010] 1A is a diagram showing an example of the configuration of a vibration presentation device 100 according to an embodiment. Fig. 1B is a diagram showing an example of a state in which the vibration presentation device 100 according to the embodiment is arranged on a seat 10 of a vehicle.

[0011] A vehicle is an example of a moving body. As shown in FIG. 1B , a seat 10 has a seat portion 11 and a backrest portion 12. FIG. 1B shows the driver's seat 10 of the vehicle. However, the vibration presentation device 100 may be arranged in a seat 10 other than the driver's seat of the vehicle. Furthermore, the moving body is not limited to a vehicle, but may be a train, a steam locomotive, an airplane, or the like. Note that, although an embodiment in which the vibration presentation device 100 is arranged in a seat of the moving body will be described here, the vibration presentation device 100 may also be arranged in a seat that is not mounted on the moving body.

[0012] As shown in FIG. 1B , the vibration presentation device 100 is disposed on the backrest 12 of the seat 10, and is used in a state where it is sandwiched between the backrest 12 and the back of a seated person. The vibration presentation device 100 includes a cushion 110 and a vibration device 140 disposed inside the cushion 110. The vibration device 140 is an example of a vibration generating unit. Details of the internal configuration of the vibration presentation device 100 will be described later with reference to FIG. 2 .

[0013] In the following, the vibration presentation device 100 may be described by defining an XYZ coordinate system. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to one another. As shown in FIG. 1B , the vibration presentation device 100 may be tilted while being placed on the backrest 12 of a vehicle seat 10. The XYZ coordinate system will be described as tilting together with the vibration presentation device 100.

[0014] The X direction is the thickness direction of the cushion 110. The cushion 110 has a surface 110A on the +X direction side and a back surface 110B on the −X direction side. The cushion 110 is placed on the seat 10 with the back surface 110B in contact with the surface of the backrest 12. As shown in FIG. 1B , when the cushion 110 is placed on the backrest 12 of the seat 10, the X direction is also the thickness direction of the backrest 12.

[0015] In the following, the relationships between front and rear, up and down, and left and right in relation to the vehicle in which the seat 10 is installed may be used in the following description. The side on which the vehicle moves forward is the front, and the side on which the vehicle moves backward is the rear. Left is the left in the forward direction of the vehicle, and right is the right in the forward direction of the vehicle. Up and down are up and down in the vertical direction. The seat 10 is installed in the interior of the vehicle facing forward of the vehicle. Therefore, the relationships between front and rear, up and down, and left and right with respect to the body of a person seated in the seat 10 correspond to the relationships between front and rear, up and down, and left and right in relation to the vehicle described above.

[0016] In the following description, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand. In Fig. 1B, the thickness of the cushion 110 in particular is exaggerated.

[0017] The vibration presentation device 100 is capable of data communication with an external device, and when a vibration presentation command is input from the external device, the vibration presentation device 100 drives the vibration device 140 to present vibration. The vibration presentation device 100 notifies the seat occupant of information by vibration. Such an external device is, for example, an electronic controller unit (ECU) of an advanced driver-assistance system (ADAS) mounted on a vehicle. When the ADAS controller detects a danger to the vehicle, it outputs a vibration presentation command to the vibration presentation device 100 via short-range wireless communication, for example.

[0018] The external device is not limited to a control device of an ADAS, and may be, for example, a navigation device, which may output a vibration command to provide route guidance.

[0019] <Details of Internal Configuration of Vibration Presentation Device 100> Fig. 2A is a diagram showing an example of the details of the internal configuration of the vibration presentation device 100. Figs. 2B and 2C are diagrams showing an example of the arrangement of the acceleration sensors 120A and 120B, the gyro sensors 125A and 125B, and the vibration device 140 in the vibration presentation device 100, and the vibration direction of the vibration device 140. Figs. 2B and 2C show the acceleration sensors 120A and 120B, the gyro sensors 125A and 125B, and the vibration device 140 arranged inside the cushion 110 in a transparent manner.

[0020] The vibration presentation device 100 includes a cushion 110, a power input terminal 115, acceleration sensors 120A and 120B, gyro sensors 125A and 125B, a pressure sensor 130, vibration devices 140A and 140B, LEDs (Light Emitting Diodes) 150, a class D amplifier 160, an MCU (Micro Controller Unit) 170, and a communication unit 180.

[0021] The acceleration sensors 120A and 120B and the gyro sensors 125A and 125B are an example of an attitude detection unit. The pressure sensor 130 is an example of a contact degree detection unit. The vibration devices 140A and 140B are an example of a vibration generation unit. The MCU 170 is an example of a control unit.

[0022] Hereinafter, when there is no need to distinguish between the acceleration sensors 120A and 120B, they will be simply referred to as acceleration sensors 120. When there is no need to distinguish between the gyro sensors 125A and 125B, they will be simply referred to as gyro sensors 125. Furthermore, the vibration presentation device 100 is required to include at least one acceleration sensor 120, and may include three or more acceleration sensors 120. The vibration presentation device 100 is required to include at least one gyro sensor 125, and may include three or more gyro sensors 125. The number of acceleration sensors 120 and the number of gyro sensors 125 may differ.

[0023] In the following description, when the vibration devices 140A and 140B are not particularly distinguished from each other, they are simply referred to as the vibration device 140. The vibration presentation device 100 may include at least one vibration device 140, and may include three or more vibration devices 140.

[0024] <Cushion 110> The cushion 110 has a structure in which a foam material such as urethane foam, foam sponge, or foam rubber is covered with a surface skin, and has cushioning properties. The cushion 110 is elastically deformable in the X direction. Since the cushion 110 is placed on the backrest 12, the back surface 110B may be curved so as to fit the surface of the backrest 12.

[0025] Of the components of the vibration presentation device 100, the acceleration sensors 120A and 120B, the gyro sensors 125A and 125B, the pressure sensor 130, the vibration devices 140A and 140B, the LED 150, the D-class amplifier 160, and the MCU 170 are provided inside the cushion 110. The cushion 110 has a sufficient thickness and appropriate elasticity so that the acceleration sensors 120A and 120B, the gyro sensors 125A and 125B, the pressure sensor 130, the vibration devices 140A and 140B, the LED 150, the D-class amplifier 160, and the MCU 170 do not come into contact with the seated occupant even when the cushion 110 is pressed by the seated occupant and contracts in the X direction.

[0026] <Power Input Terminal 115> The power input terminal 115 is a connector that can be connected to a cigarette lighter socket, a USB (Universal Serial Bus) connector, etc. of a vehicle. The power input terminal 115 obtains power from a power source such as a vehicle battery via the cigarette lighter socket, the USB connector, etc. The power input terminal 115 is connected to the class D amplifier 160 and the MCU 170 via a power cord 115A.

[0027] <Acceleration Sensors 120A, 120B> The acceleration sensors 120A, 120B are provided inside the cushion 110 and, as an example, are fixed to the vibration devices 140A, 140B as shown in Fig. 2B. As an example, the acceleration sensor 120A is arranged on the left side inside the cushion 110 together with the vibration device 140A, and the acceleration sensor 120B is arranged on the right side inside the cushion 110 together with the vibration device 140B.

[0028] The acceleration sensors 120A and 120B detect acceleration occurring in the cushion 110. The acceleration sensors 120A and 120B also detect vibrations of the vibration devices 140A and 140B. The vibrations of the vibration devices 140A and 140B are expressed as accelerations.

[0029] 2B, the acceleration sensors 120A and 120B are fixed to the ends of the vibration devices 140A and 140B on the +X direction side, respectively, as an example. This allows efficient detection of vibrations of the vibration devices 140A and 140B vibrating in the X direction. The X direction is the thickness direction of the cushion 110, and is the direction connecting the front surface 110A and the back surface 110B. Note that the acceleration sensors 120A and 120B may also be fixed to the ends of the vibration devices 140A and 140B on the -X direction side, respectively.

[0030] As an example, the acceleration sensors 120A and 120B may be MEMS (Micro Electro Mechanical Systems) acceleration sensors.

[0031] The acceleration sensor 120A detects the vibration of the vibration device 140A and outputs the vibration to the MCU 170, and the acceleration sensor 120B detects the vibration of the vibration device 140B and outputs the vibration to the MCU 170. By detecting the vibration of the vibration devices 140A and 140B and outputting the vibration to the MCU 170, the current vibration of the vibration devices 140A and 140B is fed back to the MCU 170.

[0032] The acceleration sensors 120A and 120B only need to be able to detect vibrations in the X direction of the vibration devices 140A and 140B, respectively, and do not need to be fixed to the vibration devices 140A and 140B, as shown in Fig. 2C. In this case, for example, as shown in Fig. 2C, the acceleration sensors 120A and 120B can be arranged on the +X direction side of the vibration devices 140A and 140B to efficiently detect vibrations of the vibration devices 140A and 140B. The acceleration sensors 120A and 120B may also be arranged on the -X direction side of the vibration devices 140A and 140B.

[0033] <Gyro Sensors 125A, 125B> The gyro sensors 125A, 125B are attached to the acceleration sensors 120A, 120B, for example. The gyro sensors 125A, 125B detect, as angular velocity, changes in the rotation speed and orientation of the cushion 110. For example, the gyro sensors 125A, 125B may be MEMS-type gyro sensors.

[0034] The outputs of the acceleration sensor 120A and the gyro sensor 125A represent the attitude of the cushion 110 (tilts about the X-axis, Y-axis, and Z-axis). The outputs of the acceleration sensor 120B and the gyro sensor 125B represent the attitude of the cushion 110 (tilts about the X-axis, Y-axis, and Z-axis). Therefore, the acceleration sensor 120A and the gyro sensor 125A detect the attitude of the cushion 110. The acceleration sensor 120B and the gyro sensor 125B detect the attitude of the cushion 110. The attitude of the cushion 110 is calculated by the MCU 170 using quaternions and expressed as Euler angles. The MCU 170 determines the amplitude of the vibration device 140A based on the outputs of the acceleration sensor 120A and the gyro sensor 125A, and determines the amplitude of the vibration device 140B based on the outputs of the acceleration sensor 120B and the gyro sensor 125B.

[0035] <Pressure Sensor 130> When a person is seated in the seat 10 on which the vibration presentation device 100 is arranged, the pressure sensor 130 detects the pressure applied in the thickness direction (X direction) of the cushion 110 to detect the degree of contact between the seat occupant and the cushion 110. The degree of contact represents the magnitude of the force pressing between the seat occupant (driver) and the cushion 110 when the driver is seated in the seat 10.

[0036] The pressure sensor 130 outputs the degree of contact to the MCU 170. As an example, the pressure sensor 130 may be a strain gauge type pressure sensor.

[0037] When the force of the seated occupant pressing against the cushion 110 is small, the seated occupant may not be able to perceive the vibration. Conversely, when the force of the seated occupant pressing against the cushion 110 is large, the seated occupant can perceive the vibration even if the amplitude of the vibration of the vibration device 140 is small. To ensure that the seated occupant can perceive the vibration, the vibration presentation device 100 detects the degree of contact between the seated occupant and the cushion 110 using the pressure sensor 130 and uses the detected degree of contact to drive and control the vibration device 140.

[0038] While the embodiment in which the degree of contact is detected using the pressure sensor 130 will be described here, the degree of contact may also be detected using the acceleration sensors 120A and 120B. For example, when a seated person sits on the seat 10 on which the cushion 110 is placed and the MCU 170 generates predetermined vibrations in the vibration devices 140A and 140B, the degree of contact can be detected based on changes in acceleration due to deformation of the cushion 110 detected by the acceleration sensors 120A and 120B. The acceleration sensors 120A and 120B detect acceleration due to deformation of portions of the cushion 110 near the acceleration sensors 120A and 120B. In this case, the acceleration sensors 120A and 120B are an example of a posture detection unit and an example of a contact degree detection unit. Furthermore, the degree of contact may be detected using only one of the acceleration sensors 120A and 120B.

[0039] <Vibration Devices 140A, 140B> The vibration devices 140A, 140B generate vibrations in the thickness direction (X direction) of the cushion 110. As an example, the vibration device 140A is disposed on the left side inside the cushion 110, and the vibration device 140B is disposed on the right side inside the cushion 110. As an example, an LRA (Linear Resonant Actuator) type vibration device can be used as the vibration devices 140A, 140B, and specifically, the HAPTIC (registered trademark) Reactor Heavy Type manufactured by Alps Alpine Co., Ltd. can be used.

[0040] The vibration devices 140A and 140B are driven based on a drive signal output from the MCU 170. The vibration devices 140A and 140B are connected to the MCU 170 via a class-D amplifier 160. The vibration devices 140A and 140B are driven by a drive current supplied from the class-D amplifier 160 in response to the drive signal output from the MCU 170.

[0041] <LED 150> The LED 150 is provided at a position where its emitted light can be seen from outside the cushion 110. As an example, the LED 150 is provided so that its light-emitting portion is exposed from the surface of the cushion 110. The LED 150 is provided to notify the user whether the posture of the cushion 110 relative to the seat 10 is within an appropriate range when the vibration presentation device 100 is placed on the seat 10.

[0042] For example, when the power input terminal 115 is connected to a cigarette lighter socket or a USB connector and the vibration presentation device 100 is placed on the seat 10, the MCU 170 determines whether the posture of the cushion 110 detected by the acceleration sensors 120A and 120B is within an appropriate range. If the posture of the cushion 110 is within the appropriate range, the MCU 170 causes the LED 150 to emit blue light to notify the user that the cushion 110 is properly placed. If the posture of the cushion 110 is not within the appropriate range, the MCU 170 causes the LED 150 to emit red light to prompt the user to readjust the cushion 110.

[0043] Instead of the LED 150, a speaker may be used to output voice or a predetermined sound to notify the user whether the posture of the cushion 110 relative to the seat 10 is within an appropriate range. Also, instead of the LED 150, a vibration device 140 may be used to generate vibrations to notify the user whether the posture of the cushion 110 relative to the seat 10 is within an appropriate range. In this case, for example, the vibration pattern may be made different depending on whether the posture of the cushion 110 relative to the seat 10 is within an appropriate range.

[0044] <Class-D amplifier 160> The class-D amplifier 160 has a PWM (Pulse Width Modulation) modulation circuit, a bridge circuit including MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), an LPF (Low Pass Filter), etc., and generates a PWM type drive current based on a drive signal output from the MCU 170 and power supplied from the power input terminal 115, and outputs the drive current to the vibration devices 140A and 140B. The duty ratio of the drive current is determined by the drive signal.

[0045] <MCU 170> The MCU 170 is connected to the power input terminal 115, acceleration sensors 120A and 120B, gyro sensors 125A and 125B, pressure sensor 130, LED 150, class D amplifier 160, and communication unit 180. The MCU 170 is realized by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an input / output interface, an internal bus, and the like. The MCU 170 has memory 170A. The memory 170A is a functional representation of the memory built into the MCU 170.

[0046] The MCU 170 operates using power supplied from the power input terminal 115, and when a vibration presentation command is input from an external device, generates a drive signal based on the posture of the cushion 110 detected by the acceleration sensors 120A, 120B and the gyro sensors 125A, 125B and the degree of contact detected by the pressure sensor 130. The MCU 170 generates the drive signal and outputs it to the class D amplifier 160, thereby controlling the drive of the vibration device 140. The MCU 170 is connected to the ECU of the ADAS via the communication unit 180. When a vibration presentation command is input from the ECU of the ADAS, the MCU 170 generates the drive signal to drive the vibration devices 140A, 140B. The MCU 170 can individually control the vibration devices 140A, 140B. The MCU 170 generates a drive signal for the vibration device 140A based on the attitude of the cushion 110 detected by the acceleration sensor 120A and the gyro sensor 125A and the degree of contact detected by the pressure sensor 130. The MCU 170 also generates a drive signal for the vibration device 140B based on the attitude of the cushion 110 detected by the acceleration sensor 120B and the gyro sensor 125B and the degree of contact detected by the pressure sensor 130.

[0047] The MCU 170 generates a drive signal and outputs it to the class D amplifier 160, thereby controlling the drive of the vibration devices 140A and 140B. The MCU 170 is connected to the ECU of the ADAS via the communication unit 180. When a vibration presentation command is input from the ECU of the ADAS, the MCU 170 generates a drive signal to drive the vibration devices 140A and 140B. The MCU 170 can individually control the vibration devices 140A and 140B.

[0048] Furthermore, how the MCU 170 generates a drive signal based on the posture of the cushion 110 detected by the acceleration sensors 120A, 120B and the gyro sensor 125 and the degree of contact detected by the pressure sensor 130 will be described later.

[0049] <Communication Unit 180> The communication unit 180 is, for example, a wireless communication device that performs short-range wireless communication with the ADAS ECU. Examples of short-range wireless communication include BLE (Bluetooth Low Energy (registered trademark)) and WLAN (Wireless Local Area Network). When the communication unit 180 receives a vibration notification command from the ADAS ECU, it transfers the command to the MCU 170. Note that, while a configuration in which the communication unit 180 performs wireless communication will be described here as an example, the communication unit 180 may also be configured to be connected to the ADAS ECU via a communication cable and receive the vibration notification command via the communication cable.

[0050] Furthermore, for example, if a computer system realizing cloud computing for remotely monitoring multiple vehicles can wirelessly communicate data with the communication unit 180 of each vehicle and the computer system can acquire driving data, etc. from the communication unit 180 of each vehicle, the vibration presentation device 100 may be used in each vehicle. As an example, the computer system determines whether inter-vehicle distance control, forward collision warning, collision damage mitigation braking, etc. are required based on the driving data, etc. acquired from the communication unit 180 of each vehicle. The computer system may then transmit a vibration presentation command to the communication unit 180 of the corresponding vehicle, causing the vibration presentation device 100 of the vehicle that received the vibration presentation command to vibrate the vibration devices 140A and 140B. In this way, the communication unit 180 may be configured to wirelessly communicate data with the computer system realizing cloud computing for remotely monitoring multiple vehicles, transmit driving data, etc., and receive the vibration presentation command.

[0051] 3A and 3C show an example of a state in which the vibration presentation device 100 is placed on the seat 10. Fig. 3B and 3D are diagrams showing an example of an estimation result of the attitude using the acceleration sensors 120A and 120B and the gyro sensors 125A and 125B.

[0052] FIG. 3A shows a state in which the vibration presentation device 100 is appropriately positioned relative to the seat 10, with the X-axis and Y-axis of the vibration presentation device 100 parallel to the horizontal plane. FIG. 3B shows an example of the attitude (tilts on the X-axis, Y-axis, and Z-axis) detected by the acceleration sensor 120A and gyro sensor 125A of the vibration presentation device 100 positioned as shown in FIG. 3A . The attitude (tilts on the X-axis, Y-axis, and Z-axis) is expressed by a roll angle, which is a rotation about an axis extending in the front direction of the vehicle, and a pitch angle, which is a rotation about an axis passing through the side of the vehicle. The horizontal plane is parallel to a plane including an axis connecting the left and right sides of the vehicle and an axis connecting the front and rear. Note that the attitude (tilts on the X-axis, Y-axis, and Z-axis) detected by the acceleration sensor 120B and gyro sensor 125B is the same as the attitude (tilts on the X-axis, Y-axis, and Z-axis) shown in FIG. 3B .

[0053] Fig. 3C shows a state in which the vibration presentation device 100 is disposed at an angle with respect to the seat 10, with the X-axis and Y-axis of the vibration presentation device 100 not parallel to the horizontal plane and the Z-axis not pointing vertically downward. Fig. 3D shows an example of the attitude (tilts about the X-axis, Y-axis, and Z-axis) detected by the acceleration sensor 120A and the gyro sensor 125A of the vibration presentation device 100 disposed as shown in Fig. 3C. Note that the attitude (tilts about the X-axis, Y-axis, and Z-axis) detected by the acceleration sensor 120B and the gyro sensor 125B is the same as the attitude (tilts about the X-axis, Y-axis, and Z-axis) shown in Fig. 3D.

[0054] 3B and 3D , the horizontal axis represents time, and the vertical axis represents the attitude angle. As an example, the vibration presentation device 100 calculates the average value of the attitude angle detected by the acceleration sensor 120A and the gyro sensor 125A and the attitude angle detected by the acceleration sensor 120B and the gyro sensor 125B, and uses the average value of the attitude angles to calculate the attitude of the cushion 110. However, as an example, the vibration presentation device 100 may calculate the attitude of the cushion 110 using the attitude angle detected by the acceleration sensor 120A and the gyro sensor 125A, or may calculate the attitude of the cushion 110 using the attitude angle detected by the acceleration sensor 120B and the gyro sensor 125B.

[0055] When the vibration presentation device 100 is properly positioned with respect to the seat 10 as shown in FIG. 3A, the roll angle and pitch angle are 0 as shown in FIG. 3B.

[0056] In contrast, when the vibration presentation device 100 is disposed so that the Z axis of the vibration presentation device 100 is tilted to the right with respect to the seat 10 as shown in Fig. 3C , the pitch angle is, for example, about 45 degrees and the roll angle is, for example, 0 degrees as shown in Fig. 3D . In Fig. 3C , the vibration presentation device 100 is not disposed appropriately with respect to the seat 10.

[0057] As described above, if the vibration presentation device 100 is not properly positioned with respect to the seat 10, the vibrations of the vibration devices 140A and 140B may not be properly transmitted to the seated occupant. For this reason, when the vibration presentation device 100 is positioned on the seat 10, the vibration presentation device 100 detects the posture of the cushion 110 and determines whether the posture is proper. If the posture of the cushion 110 is not proper, the vibration presentation device 100 causes the LED 150 to emit red light to notify the user that the positioning of the cushion 110 is improper, and requests the user to reposition the cushion 110. If the posture of the cushion 110 is proper, the vibration presentation device 100 causes the LED 150 to emit blue light to notify the user that the positioning of the cushion 110 is proper.

[0058] 3A to 3D, a case where the vibration presentation device 100 is disposed so that its Z axis is tilted to the right, resulting in an inappropriate placement of the vibration presentation device 100 relative to the seat 10. However, the same applies to a case where the vibration presentation device 100 is disposed so that its Z axis is tilted to the left, front, rear, or a combination of these, and the tilt is relatively large, resulting in an inappropriate placement of the vibration presentation device 100 relative to the seat 10.

[0059] The threshold value for determining whether the placement of the vibration presentation device 100 relative to the seat 10 is inappropriate may be set, for example, according to the elasticity of the cushion 110 and the vibration characteristics of the vibration devices 140A and 140B. In addition to the elasticity of the cushion 110 and the vibration characteristics of the vibration devices 140A and 140B, the threshold value may be set taking into consideration the elasticity of the backrest 12, or the threshold value may be set by the user.

[0060] <Method of Generating Drive Signal> Fig. 4 is a diagram illustrating an example of a method of generating a drive signal. Fig. 4 shows the acceleration sensor 120, the gyro sensor 125, the pressure sensor 130, and the MCU 170, and also shows the flow of data inside the MCU 170.

[0061] <Calculation of attitude coefficient α> When the vibration device 140 is not vibrating and the cushion 110 is placed on the seat, the MCU 170 calculates the attitude coefficient α based on data representing the attitude of the cushion 110 (tilts about the X-axis, Y-axis, and Z-axis) detected by the acceleration sensor 120 and the gyro sensor 125. The more the attitude of the cushion 110 detected by the acceleration sensor 120 is tilted, the larger the value of the attitude coefficient α that the MCU 170 calculates.

[0062] As an example, the MCU 170 calculates the attitude coefficient α using equations (1A) and (1B). ｐ is the pitch angle detected by the acceleration sensor 120 and the gyro sensor 125. For example, the MCU 170 calculates a pitch angle estimated value obtained by applying a low-pass filter to the acceleration in three directions detected by the acceleration sensor 120A or a value obtained by applying a high-pass filter to the acceleration in three directions and a value obtained by applying a high-pass filter to the angular velocity detected by the gyro sensor 125A as d ｐ For example, the MCU 170 may use the pitch angle estimated value obtained from the acceleration in three directions detected by the acceleration sensor 120B or a value obtained by applying a low-pass filter to the acceleration in three directions and a value obtained by applying a high-pass filter to the angular velocity detected by the gyro sensor 125B as d ｐ It can be used as:

[0063]

[0064] Equation (1A) is the pitch angle d ｐ is a formula for calculating the attitude coefficient α when the pitch angle d is equal to or greater than 0 degrees and less than 45 degrees. ｐ When the pitch angle d is between 0 degrees and 45 degrees, the attitude coefficient α is set to a fixed value of 1.5. In other words, the attitude coefficient α can take a value within the range of 1 to 1.5. The pitch angle d obtained based on the outputs of the acceleration sensors 120A and 120B and the gyro sensors 125A and 125B is ｐ becomes larger as the posture of the cushion 110 is tilted, and therefore the value of the posture coefficient α becomes larger as the posture of the cushion 110 is tilted.

[0065] The equations for calculating the posture coefficient α are not limited to equations (1A) and (1B), and the coefficients of each term may be set to appropriate values ​​taking into account the elasticity of the cushion 110, the elasticity of the backrest portion 12, etc.

[0066] <Calculation of Contact Coefficient β> The MCU 170 calculates the contact coefficient β based on data indicating the degree of contact detected by the pressure sensor 130. The degree of contact is, for example, the pressure detected by the pressure sensor 130. The MCU 170 calculates the contact coefficient β to be a larger value as the degree of contact detected by the pressure sensor 130 decreases.

[0067] As an example, the MCU 170 calculates the contact coefficient β using the following equation (2): p is the pressure (digital value) detected by the pressure sensor 130 and takes a positive value; k is a coefficient. The coefficient k is set so that the contact coefficient β takes a value within the range of 0 to 1. Therefore, the smaller the pressure p, the larger the contact coefficient β becomes, approaching 1.

[0068]

[0069] <Acceleration FB value A ｆｂ Calculation of acceleration g in the X direction detected by the acceleration sensor 120 while the vibration device 140 is vibrating ｘ Based on this, the estimated vibration amplitude G ａｃｔｕａｌAs an example, the average value of the acceleration in the X direction detected by the two acceleration sensors 120A and 120B is calculated as g ｘ It can be used as:

[0070] The MCU 170 calculates the acceleration g in the X direction. ｘ By performing a Discrete Fourier Transform (DFT) or a Hilbert Transform on the vibration amplitude G, the actual vibration amplitude of the vibration devices 140A and 140B in the X direction is estimated. ａｃｔｕａｌ The estimated vibration amplitude G ａｃｔｕａｌ is an estimated value of the amplitude of vibration in the X direction of the vibration devices 140A and 140B. Note that since the amplitudes of vibration in the X direction of the vibration devices 140A and 140B are equal, the average value of the acceleration in the X direction detected by the two acceleration sensors 120A and 120B is g ｘ By using the above, the estimated vibration amplitude G ａｃｔｕａｌ can be obtained.

[0071] The MCU 170 further calculates the estimated vibration amplitude G ａｃｔｕａｌ Acceleration FB value A ｆｂ Calculate the acceleration FB value A ｆｂ is a feedback value of the amplitude of acceleration of vibration in the X direction of the vibration devices 140A and 140B, and is an input voltage value to the vibration devices 140A and 140B calculated from the acceleration amplitude. Specifically, the MCU 170 calculates the estimated vibration amplitude G ａｃｔｕａｌ and a target acceleration G representing a target acceleration amplitude value. ｔａｒｇｅｔ The proportional, differential, and integral terms of acceleration are calculated using PID control using the deviation from the acceleration. The acceleration FB value A is calculated by taking the sum of the proportional, differential, and integral terms. ｆｂ Ask for.

[0072] <Reference vibration amplitude G ｒｅｆ The MCU 170 determines the reference vibration amplitude G ｒｅｆ The data representing the reference vibration amplitude G is stored in the memory 170A. ｒｅｆis a reference value of the amplitude of the acceleration of the vibration of the vibration devices 140A and 140B, and its value is determined depending on the type of vibration presentation command input from the ADAS ECU to the MCU 170. The type of vibration presentation command corresponds to the type of warning specified by the ADAS ECU. The types of warning include, for example, following distance control, forward collision warning, collision damage mitigation braking, night vision, pedestrian detection, lane departure warning, lane departure prevention assistance, etc. Depending on these types, the reference vibration amplitude G ｒｅｆ The values ​​are different.

[0073] <Target vibration amplitude G ｔａｒｇｅｔ The MCU 170 generates the contact coefficient β, the attitude coefficient α, and the reference vibration amplitude G ｒｅｆ Using the above, the target vibration amplitude G is calculated based on the following equation (3): ｔａｒｇｅｔ The target vibration amplitude G ｔａｒｇｅｔ is the target value of the amplitude of the acceleration of the vibration of the vibration devices 140A and 140B in the X direction.

[0074]

[0075] Target vibration amplitude G ｔａｒｇｅｔ The larger the target vibration amplitude G ｔａｒｇｅｔ The smaller the value of θ is, the smaller the amplitude of vibration of the vibration devices 140A and 140B in the X direction is.

[0076] Target vibration amplitude G ｔａｒｇｅｔ The larger the attitude coefficient α, the larger the target vibration amplitude G ｔａｒｇｅｔ The larger the contact coefficient β, the larger the target vibration amplitude G ｔａｒｇｅｔ is the reference vibration amplitude G ｒｅｆ The larger the is, the larger it becomes.

[0077] <Target voltage amplitude A ｔａｒｇｅｔ The MCU 170 generates the target vibration amplitude G ｔａｒｇｅｔ and the target voltage amplitude A ｔａｒｇｅｔ A look-up table (LUT) storing the relationship between the target voltage amplitude A and the target voltage amplitude A is stored in the memory 170A. ｔａｒｇｅｔ is the amplitude of the acceleration of the vibration of the vibration devices 140A and 140B in the X direction, which is the target vibration amplitude Gｔａｒｇｅｔ In the LUT, the target vibration amplitude G ｔａｒｇｅｔ and the target voltage amplitude A ｔａｒｇｅｔ is in a proportional relationship.

[0078] The MCU 170 determines the target vibration amplitude G ｔａｒｇｅｔ Using the above, the target voltage amplitude A ｔａｒｇｅｔ The target vibration amplitude G ｔａｒｇｅｔ and the target voltage amplitude A ｔａｒｇｅｔ The relationship between these is expressed by the following equation (4).

[0079]

[0080] <Calculation of Amplitude A of Drive Signal> The amplitude A of the drive signal is the amplitude of the voltage applied to the vibration devices 140A and 140B. The MCU 170 calculates the acceleration FB value A according to the following equation (5): ｆｂ and the target voltage amplitude A ｔａｒｇｅｔ The amplitude A of the drive signal is calculated by adding

[0081]

[0082] In this way, the MCU 170 can calculate the amplitude A of the drive signals of the vibration devices 140A and 140B based on the posture of the cushion 110 determined based on the outputs of the acceleration sensor 120 and the gyro sensor 125 and the degree of contact detected by the pressure sensor 130.

[0083] Using the amplitude A, the drive signal F(t) can be expressed by the following equation (6): where ω is the angular velocity of the vibration and t is time.

[0084]

[0085] The MCU 170 controls the driving of the vibration devices 140A and 140B using the driving signal F(t) including the amplitude A expressed by equation (5).

[0086] Therefore, the MCU 170 controls the driving of the vibration device 140 so that the amplitude A of the vibration of the vibration device 140 increases as the attitude of the cushion 110 determined based on the outputs of the acceleration sensor 120 and the gyro sensor 125 becomes more tilted. Furthermore, the MCU 170 controls the driving of the vibration device 140 so that the amplitude A of the vibration of the vibration device 140 increases as the degree of contact detected by the pressure sensor 130 decreases.

[0087] <Flowchart> FIG. 5 is a flowchart showing an example of processing executed by the MCU 170.

[0088] When the power is turned on, the MCU 170 starts processing (step S1). The user of the vibration presentation device 100 understands that when the vibration presentation device 100 is placed on the seat 10, the vibration presentation device 100 detects the posture of the cushion 110 and determines whether the posture is within an appropriate range.

[0089] The MCU 170 detects the attitude of the cushion 110 based on the outputs of the acceleration sensors 120A and 120B and the gyro sensors 125A and 125B (step S2).

[0090] The MCU 170 determines whether the posture of the cushion 110 thus determined is within an appropriate range (step S3).

[0091] If the MCU 170 determines that the posture of the cushion 110 is not within the appropriate range (S3: No), it causes the LED 150 to emit red light (step S4). When the LED 150 emits red light, the user understands that the posture of the cushion 110 is not appropriate, and places the cushion 110 back on the seat 10. After completing the processing of step S4, the MCU 170 returns the flow to step S2.

[0092] When the MCU 170 determines in step S3 that the posture of the cushion 110 is within the appropriate range (S3: Yes), it causes the LED 150 to emit blue light (step S5). When the LED 150 emits blue light, the user understands that the posture of the cushion 110 is appropriate, and sits on the seat 10 with the cushion 110 in that position.

[0093] The MCU 170 determines the target vibration amplitude G ｔａｒｇｅｔ and the target voltage amplitude A ｔａｒｇｅｔ The MCU 170 determines whether to recreate the LUT that stores the relationship between the LUT and the vibration presentation device 100 (step S6). For example, the LUT may be recreated when the power is turned on for the first time on the day that the user uses the vibration presentation device 100, and may not be recreated when the power is turned on for the second or subsequent time. The MCU 170 may be configured to recreate the LUT when the user inputs a command to reset the LUT.

[0094] When the MCU 170 determines that the LUT is to be generated (S6: Yes), the target vibration amplitude G ｔａｒｇｅｔ and the target voltage amplitude A ｔａｒｇｅｔ (Step S7) After completing the process of Step S7, the MCU 170 advances the flow to Step S8.

[0095] If the MCU 170 determines in step S6 that an LUT is not to be generated (S6: No), the flow proceeds to step S8.

[0096] Steps S8 to S16 are loop processes.

[0097] The MCU 170 acquires the posture of the cushion 110 detected by the acceleration sensors 120A, 120B and the gyro sensors 125A, 125B, the degree of contact detected by the pressure sensor 130, and the acceleration amplitude values ​​of the vibration devices 140A, 140B (step S8). The degree of contact is the pressure p detected by the pressure sensor 130. The acceleration amplitude values ​​of the vibration devices 140A, 140B are values ​​that represent the amplitude of vibration of the vibration devices 140A, 140B detected by the acceleration sensor 120.

[0098] The MCU 170 determines whether a vibration presentation command has been input from the ECU of the ADAS (step S9).

[0099] When the MCU 170 determines that a vibration presentation command has been input (S9: Yes), it determines whether the seated occupant is leaning against the cushion 110 based on the degree of contact acquired in step S8 (step S10). In step S10, if the pressure p detected by the pressure sensor 130 is equal to or greater than a predetermined small pressure when the seated occupant is leaning against the cushion 110, the MCU 170 determines that the seated occupant is leaning against the cushion 110.

[0100] When the MCU 170 determines that the seated occupant is leaning on the cushion 110 (S10: Yes), the MCU 170 sets the reference vibration amplitude G ｒｅｆ is obtained from the memory 170A (step S11).

[0101] The MCU 170 calculates the posture and contact degree of the cushion 110 acquired in step S8 and the reference vibration amplitude G ｒｅｆ Based on this, the target vibration amplitude G ｔａｒｇｅｔ Specifically, the MCU 170 calculates the attitude coefficient α using equation (1A) or (1B), calculates the contact coefficient β using equation (2), and generates the target vibration amplitude G ｔａｒｇｅｔ The MCU 170 calculates the contact coefficient β and the target vibration amplitude G for each of the vibration devices 140A and 140B. ｔａｒｇｅｔ Calculate.

[0102] The MCU 170 uses the LUT to obtain the target vibration amplitude G ｔａｒｇｅｔ Target voltage amplitude A corresponding to ｔａｒｇｅｔ The MCU 170 calculates the target voltage amplitude A for each of the vibration devices 140A and 140B (step S13). ｔａｒｇｅｔ Ask for.

[0103] The MCU 170 determines the target vibration amplitude G ｔａｒｇｅｔ and estimated vibration amplitude G ａｃｔｕａｌ Therefore, the acceleration FB value A ｆｂ The MCU 170 calculates the acceleration FB value A for each of the vibration devices 140A and 140B (step S14). ｆｂ Ask for.

[0104] The MCU 170 calculates the acceleration FB value A according to the formula (5). ｆｂ and the target voltage amplitude A ｔａｒｇｅｔ The MCU 170 calculates the amplitude A of the drive signal by adding the amplitudes A and B (step S15).

[0105] The MCU 170 controls the driving of the vibration devices 140A and 140B with the driving signal F(t) expressed by equation (6) using the amplitude A (step S16). After completing the process of step S16, the MCU 170 returns the flow to step S8 and performs loop processing.

[0106] If the MCU 170 determines in step S9 that a vibration presentation command has not been input (S9: No), it skips steps S10 to S16 and performs the loop process again from step S8.

[0107] Furthermore, if the MCU 170 determines in step S10 that the seated occupant is not leaning on the cushion 110 (S10: No), it skips steps S11 to S16 and starts the loop process again from step S8.

[0108] This completes the series of processes.

[0109] <Effects> The vibration presentation device 100 includes a cushion 110 that can be placed on a seat 10 of a moving body, an acceleration sensor 120 and a gyro sensor 125 (posture detection unit) that detect the posture of the cushion 110, a pressure sensor 130 (contact degree detection unit) that detects the degree of contact between an occupant sitting on the seat 10 on which the cushion 110 is placed and the cushion 110, a vibration device 140 (vibration generation unit) that vibrates the cushion 110, and an MCU 170 (control unit) that controls the drive of the vibration device 140 based on the posture of the cushion 110 detected by the acceleration sensor 120 and the degree of contact detected by the pressure sensor 130. Therefore, it is possible to present vibrations to the occupant using the vibration device 140, which is drive-controlled based on the posture of the cushion 110 that can be placed on the seat 10 and the degree of contact.

[0110] Therefore, it is possible to provide a vibration presentation device 100 that can be retrofitted to the seat 10 of a moving body and that can present vibrations that can be perceived by the seated person.

[0111] The cushion 110 may also be arranged in the backrest 12 of the seat 10. By being arranged between the backrest 12 and the back of the seated person, the vibration of the vibration device 140 can be efficiently presented to the back of the seated person.

[0112] Furthermore, the MCU 170 may control the driving of the vibration device 140 so that the amplitude of vibration of the vibration device 140 increases as the posture of the cushion 110 detected by the acceleration sensor 120 becomes more tilted. Since the vibration is less transmitted as the posture of the cushion 110 becomes more tilted, by increasing the amplitude of vibration, it is possible to provide a vibration presentation device 100 that can present vibrations that can be more reliably perceived by the seated person.

[0113] Furthermore, the MCU 170 may control the driving of the vibration device 140 so that the amplitude of vibration of the vibration device 140 increases as the degree of contact detected by the pressure sensor 130 decreases. Since the smaller the degree of contact, the more difficult it is for vibration to be transmitted, by increasing the amplitude of vibration, it is possible to provide a vibration presentation device 100 that can present vibrations that can be more reliably perceived by the seated occupant.

[0114] Furthermore, when a vibration presentation command is input from an external device that outputs the vibration presentation command, the MCU 170 may control the driving of the vibration device 140 based on the posture of the cushion 110 detected by the acceleration sensor 120 and the degree of contact detected by the pressure sensor 130. It is possible to provide a vibration presentation device 100 that can be retrofitted to the seat 10 of a moving object and that can present vibrations that can be perceived by the seated occupant when a vibration presentation command is input from an external device.

[0115] Furthermore, when an occupant is seated on the seat 10 on which the cushion 110 is arranged and the MCU 170 generates a predetermined vibration in the vibration device 140, the degree of contact may be detected based on the posture of the cushion 110 detected by the acceleration sensor 120 and the gyro sensor 125. By detecting the degree of contact using the acceleration sensor 120 without using the pressure sensor 130, it is possible to provide a vibration presentation device 100 that can present vibrations that can be perceived by the seated occupant.

[0116] Furthermore, a single acceleration sensor may be used to configure the acceleration sensor 120 and the pressure sensor 130. By detecting the degree of contact and the posture of the cushion 110 using a single acceleration sensor 120 without using the pressure sensor 130, it is possible to provide a vibration presentation device 100 that can be retrofitted to the seat 10 of a moving object and present vibrations that can be perceived by the seated person, while simplifying the configuration.

[0117] The above describes a vibration presentation device according to an exemplary embodiment of the present disclosure, but the present disclosure is not limited to the specifically disclosed embodiment, and various modifications and variations are possible without departing from the scope of the claims.

[0118] This international application claims priority based on Japanese Patent Application No. 2024-097838, filed on June 18, 2024, the entire contents of which are incorporated herein by reference.

[0119] REFERENCE SIGNS LIST 10 seat 11 seat portion 12 backrest portion 100 vibration presentation device 110 cushion 115 power input terminal 120, 120A, 120B acceleration sensor (an example of an attitude detection unit) 125, 125A, 125B gyro sensor (an example of an attitude detection unit) 130 pressure sensor (an example of a contact degree detection unit) 140, 140A, 140B vibration device (an example of a vibration generation unit) 150 LED 160 Class D amplifier 170 MCU (an example of a control unit) 180 communication unit

Claims

1. A vibration presentation device comprising: a cushion that can be placed on a seat; a posture detection unit that detects the posture of the cushion; a contact degree detection unit that detects the degree of contact between an occupant sitting on the seat on which the cushion is placed and the cushion; a vibration generation unit that vibrates the cushion; and a control unit that controls the drive of the vibration generation unit based on the posture of the cushion detected by the posture detection unit and the degree of contact detected by the contact degree detection unit.

2. The vibration presentation device according to claim 1, wherein the cushion can be placed on the back of the seat.

3. The vibration presentation device of claim 2, wherein the control unit controls the drive of the vibration generating unit so that the amplitude of vibration of the vibration generating unit increases as the posture of the cushion detected by the posture detection unit becomes more tilted.

4. A vibration presentation device as claimed in any one of claims 1 to 3, wherein the control unit controls the drive of the vibration generating unit so that the amplitude of vibration of the vibration generating unit increases as the degree of contact detected by the contact degree detection unit decreases.

5. A vibration presentation device as described in any one of claims 1 to 4, wherein when a vibration presentation command is input from an external device that outputs the vibration presentation command, the control unit controls the drive of the vibration generating unit based on the posture of the cushion detected by the posture detection unit and the degree of contact detected by the contact degree detection unit.

6. A vibration presentation device as described in any one of claims 1 to 5, wherein the contact degree detection unit detects the degree of contact by detecting the posture of the cushion when an occupant is seated on the seat on which the cushion is placed and the control unit generates a predetermined vibration in the vibration generating unit.

7. The vibration presentation device according to claim 6, wherein the contact degree detection unit is configured with one acceleration sensor.

8. The vibration presentation device according to claim 6, wherein the cushion can be placed on a seat of a moving body, and the posture detection unit and the contact degree detection unit are configured with one acceleration sensor and one gyro sensor.

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