Seat state detection device, program, and seat state detection method

Abstract

This seat state sensing device comprises: a first vibration detector installed on a seat provided to a vehicle, the first vibration detector detecting vibration and outputting a first vibration signal; a second vibration detector installed on the vehicle body near the seat, the second vibration detector detecting vibration and outputting a second vibration signal; a first calculation unit for calculating the similarity degree between the first vibration signal inputted from the first vibration detector and the second vibration signal inputted from the second vibration detector; and a sensing unit for sensing, on the basis of the similarity degree calculated by the first calculation unit, the seat state including at least one of the slide position of the seat with respect to the longitudinal direction of the vehicle body, the reclining angle of the seat, and the direction of the seat with respect to the longitudinal direction of the vehicle body.

Description

[Technical Field]

[0001] The present disclosure relates to a seat state detection device, a program, and a seat state detection method that automatically detect seat states such as seat orientation and reclining angle in transportation means having seats for passengers, such as automobiles, trains, airplanes, and ships. [Background technology]

[0002] Patent Document 1 listed below discloses a system that can encourage a driver to adopt an appropriate driving posture according to the driver's physique.

[0003] Patent Document 2 listed below shows a seat equipped with a seat heater that gives a comfortable warmth to the seated person depending on the reclining state of the seat.

[0004] Patent Document 3 listed below discloses a device that deploys an airbag appropriately depending on the seating position of the occupant, which varies depending on individual differences such as physique and driving posture.

[0005] The following Patent Document 4 discloses an airbag device that appropriately deploys an airbag by distinguishing between an occupant seated on a seat and baggage placed on the seat.

[0006] Patent Document 5 listed below discloses an active noise control (ANC) device that appropriately controls noise inside a vehicle cabin even when the seat position or reclining angle changes.

[0007] Patent Document 6 listed below discloses a noise control filter that uses a detection means to detect the seat in which an occupant is seated and efficiently controls noise by limiting it to that position.

[0008] Patent Document 7 listed below shows a train seat direction changing device that makes it easier to turn all seats in a certain direction during turnaround operations or cleaning, and can reduce the time required for the work.

[0009] As shown in Patent Documents 1 to 7, in seat state detection related to the background art, methods of directly measuring physical quantities related to the seat, such as seat position, angle, load, and distance, have generally been used, and seat state detection using factors that are not directly related to the seat itself has not been used. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-201174 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-52850 [Patent Document 3] Japanese Patent Application Publication No. 5-213142 [Patent Document 4] Japanese Patent Application Publication No. 8-216824 [Patent Document 5] Japanese Patent Application Laid-Open No. 2008-149922 [Patent Document 6] Japanese Patent Application Laid-Open No. 2010-54962 [Patent Document 7] Japanese Patent Application Publication No. 10-157619 Summary of the Invention

[0011] The present disclosure aims to provide a seat state detection device that can detect seat states such as seat slide position, reclining angle, and seat direction at low cost using vibration signals from a vehicle.

[0012] A seat state detection device according to one embodiment of the present disclosure includes at least one first vibration detector installed in at least one seat of a vehicle, detecting vibrations and outputting a first vibration signal; at least one second vibration detector installed in the vehicle body near the seat, detecting vibrations and outputting a second vibration signal; a first calculation unit that calculates a similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; and a detection unit that detects the seat state based on the similarity calculated by the first calculation unit, including at least one of the sliding position of the seat in the fore-and-aft direction of the vehicle body, the reclining angle of the seat, and the orientation of the seat relative to the fore-and-aft direction of the vehicle body. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a configuration diagram of a seat state detection device according to a first embodiment. [Figure 2] FIG. 2 is a configuration diagram showing a noise control filter. [Figure 3] This is a side view of the driver's seat. [Figure 4] FIG. 10 is a configuration diagram of a seat state detection device according to a second embodiment. [Figure 5] This is a side view of the driver's seat. [Figure 6] This is a diagram showing the seating arrangement inside the train as seen from above. [Figure 7] FIG. 10 is a configuration diagram of a seat state detection device according to a second embodiment. [Figure 8] FIG. 10 is a configuration diagram of a seat state detection device according to a third embodiment. [Figure 9] This is a side view of the seat. [Figure 10] FIG. 10 is a configuration diagram of a seat state detection device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Findings that formed the basis of this disclosure) There are many means of transportation that have seats, but automobiles in particular are assumed to have all occupants seated, and various controls have been proposed according to the seating status of the occupants.

[0015] For example, Patent Document 1 discloses a system that can encourage a driver to adopt an appropriate driving posture according to their physique, and uses a camera as a means to achieve this. Specifically, the system obtains the driver's physique (sitting height) and the reclining angle and sliding amount of the driver's seat from an image captured by a camera inside the vehicle, and controls the driver's seat so that the reclining angle and sliding amount match the recommended values ​​according to the driver's physique.

[0016] Patent Document 2 discloses a seat equipped with a seat heater that provides a comfortable warmth to the occupant depending on the seat's reclining position. This is achieved by using an angle sensor that detects the inclination of the seat back. Specifically, the angle sensor installed in the seat detects the seat back's inclination angle. If the angle deviates from the standard position and determines that the seat is not in close contact with the occupant's body, the seat heater increases its heat output to provide the occupant with an appropriate warmth. Alternatively, if the inclination angle is large, such as when fully reclined (the seat back is tilted back significantly), the system determines that the occupant is relaxed and controls the seat heater to a low temperature to allow for a good night's sleep or to prevent burns from low temperatures. Examples of angle sensors include variable resistors, rotary encoders, position sensors, and gyro sensors.

[0017] Next, Patent Document 3 discloses a device that appropriately deploys an airbag according to the seating position of the occupant, which varies depending on individual differences such as physique and driving posture. To achieve this, a seat position detection means that detects the sliding position of the seat and a seat back angle detection means that detects the rotation angle of the seat back are used. Specifically, the occupant's head position is estimated from information detected by the seat position detection means and the seat back angle detection means, and the airbag deployment condition level is increased or decreased according to the estimated value. More specifically, if the head position is close to the steering wheel, the airbag is set to be more likely to deploy. Here, a contact type is exemplified for the seat position detection means and the seat back angle detection means.

[0018] Patent Document 4 also discloses an airbag device that appropriately deploys an airbag by distinguishing between an occupant and luggage placed on the seat. To achieve this, a seat position detection unit detects the longitudinal position of the seat, a seatback angle detection unit detects the tilt angle of the seatback, and a distance measurement unit measures the distance to the occupant or seatback. Specifically, the distance between a reference point (the position where the distance measurement unit is installed) and the seatback is calculated from the detected values ​​of the seat position detection unit and the seatback angle detection unit. The presence or absence of an occupant in the seat is determined based on the difference between this calculated value and the distance measured directly by the distance measurement unit, and the timing and speed of airbag deployment are controlled. Furthermore, the necessity of airbag deployment is controlled by distinguishing between an occupant and luggage. Here, examples of the seat position detection unit and the seatback angle detection unit include a seatback angle sensor and a seat position sensor each composed of a potentiometer (variable resistor), and examples of the distance measurement unit include an ultrasonic sensor.

[0019] Next, Patent Document 5 discloses an active noise control (ANC) device that appropriately controls noise inside a vehicle cabin even when the seat position or reclining angle changes. To achieve this, a detection means is used to detect the seat position or seatback angle, which refer to the front-to-rear and up-down directions of the vehicle. Specifically, based on the seat position detected by a position sensor and the seatback angle detected by an angle sensor, the transfer characteristics set in the correction means from the speaker that reproduces a canceling sound for the noise to the microphone that detects an error signal between the canceling sound and the noise can be switched to appropriate characteristics, thereby appropriately determining the coefficients of an adaptive filter that outputs a control signal for canceling the noise. Here, variable resistors are exemplified as the position sensor and the angle sensor.

[0020] Patent Document 6 also discloses a noise control filter in which a detection means detects the seat in which an occupant is seated and efficiently controls noise only at that position. To achieve this, a load sensor installed under the seat or on the back of the seat (seatback) is used as an occupant presence / absence detection sensor. Specifically, the load sensor distinguishes between seats in which an occupant is seated and seats in which an occupant is not seated, and instead of performing noise control in seats in which an occupant is seated, a finite number of actuators (speakers) that play control sounds, for example, are effectively used to expand the control space. Here, an example of an occupant presence / absence detection sensor is shown to be an electric charge type.

[0021] So far we have been talking about automobiles, but trains also have seats for passengers, but unlike automobiles, they have multiple seats integrated into one unit and have the advantage of being able to rotate.

[0022] Patent Document 7 discloses a train seat direction changing device that facilitates the task of orienting all seats in a certain direction during turnarounds or cleaning, and can reduce the time required for this task. To achieve this, a direction detection sensor that detects the seat direction and a reference position detection sensor that detects whether the seats are in a reference position are used. Specifically, the direction detection sensor detects the rotation position of the seat to determine whether the seat direction is in a predetermined direction, and the reference position detection sensor determines whether the seat is in its initial position (not reclined), unlocking only the seats in the initial position in the predetermined direction and simultaneously changing the orientation of all unlocked seats.

[0023] In the past, various services and value have been provided to passengers seated in seats not only in automobiles and trains but also in aircraft, etc. However, detection of seat status, including the presence or absence of a passenger, has generally been achieved by directly measuring physical quantities related to the seat, such as seat position, angle, load, and distance, and detection of seat status using factors not directly related to the seat itself has not been used.

[0024] Furthermore, although the active noise control (ANC) systems in Patent Documents 5 and 6 have means for detecting noise, these noise detection means are not used, and instead additional seat position sensors, angle sensors, load sensors, etc. are used, which increases costs.

[0025] In order to solve this problem, the inventor discovered that by utilizing the similarity between vibrations detected by a vibration detector installed in a vehicle seat and vibrations detected by a vibration detector installed in the vehicle body near the seat, it is possible to easily and low-costly detect the seat state, including at least one of the seat slide position, reclining angle, and seat direction, and came up with the present disclosure.

[0026] Next, each aspect of the present disclosure will be described.

[0027] A seat state detection device according to one embodiment of the present disclosure includes at least one first vibration detector installed in at least one seat of a vehicle, detecting vibrations and outputting a first vibration signal; at least one second vibration detector installed in the vehicle body near the seat, detecting vibrations and outputting a second vibration signal; a first calculation unit that calculates a similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; and a detection unit that detects the seat state based on the similarity calculated by the first calculation unit, including at least one of the sliding position of the seat in the fore-and-aft direction of the vehicle body, the reclining angle of the seat, and the orientation of the seat relative to the fore-and-aft direction of the vehicle body.

[0028] According to this aspect, the first calculation unit calculates the similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector, and the detection unit detects the seat state based on the similarity, thereby making it possible to detect the seat state of seats installed in a vehicle easily and at low cost.

[0029] In the above aspect, the at least one second vibration detector has a plurality of second vibration detectors installed at a distance from each other in the fore-and-aft direction of the vehicle body, the seat state includes the sliding position of the seat in the fore-and-aft direction of the vehicle body, the first calculation unit calculates a plurality of similarities between the first vibration signal and a plurality of second vibration signals input from the plurality of second vibration detectors, and the detection unit detects the sliding position of the seat in the fore-and-aft direction of the vehicle body based on the multiple similarities calculated by the first calculation unit.

[0030] According to this aspect, by installing multiple second vibration detectors at a distance from each other in the fore-and-aft direction of the vehicle body and having the detection unit detect the sliding position of the seat based on multiple similarities, it is possible to improve detection accuracy.

[0031] In the above aspect, the at least one second vibration detector has a plurality of second vibration detectors installed at a distance from each other in the vertical direction of the vehicle body, the seat state includes the reclining angle of the seat, the first calculation unit calculates a plurality of similarities between the first vibration signal and a plurality of second vibration signals input from the plurality of second vibration detectors, and the detection unit detects the reclining angle of the seat based on the multiple similarities calculated by the first calculation unit.

[0032] According to this aspect, by installing multiple second vibration detectors at a distance from each other in the vertical direction of the vehicle body and having the detection unit detect the seat reclining angle based on multiple similarities, it is possible to improve detection accuracy.

[0033] In the above aspect, the at least one seat includes a plurality of seats that are connected and installed in the left-right direction of the vehicle body and whose reclining angles can be adjusted independently, and the at least one first vibration detector includes a plurality of first vibration detectors installed on the plurality of seats and further includes a second calculation unit that calculates the similarity between the plurality of first vibration signals input from the plurality of first vibration detectors, and the detection unit further detects the relative reclining angles between the plurality of seats based on the similarity calculated by the second calculation unit.

[0034] According to this aspect, the detection unit detects the relative reclining angles between multiple seats that are connected and installed in the left-right direction of the vehicle body, thereby making it possible to detect the absolute reclining angles of each of the multiple seats.

[0035] In the above aspect, the at least one seat includes a plurality of seats connected and installed in the left-right direction of the vehicle body, the at least one first vibration detector includes a plurality of first vibration detectors installed on the plurality of seats, the seat state includes the orientation of the seat with respect to the fore-and-aft direction of the vehicle body, the first calculation unit calculates a plurality of similarities between a plurality of first vibration signals input from the plurality of first vibration detectors and the second vibration signal input from the second vibration detector, and the detection unit detects the orientation of the plurality of seats with respect to the fore-and-aft direction of the vehicle body based on the multiple similarities calculated by the first calculation unit.

[0036] According to this aspect, multiple first vibration detectors are installed on multiple seats that are connected in the left-right direction of the vehicle body, and the detection unit detects the orientation of the seats based on multiple similarities, thereby making it possible to improve detection accuracy.

[0037] In the above aspect, the at least one first vibration detector includes a plurality of first vibration detectors installed on the left and right sides of the seat, the seat state includes the orientation of the seat relative to the fore-and-aft direction of the vehicle body, the first calculation unit calculates a plurality of similarities between a plurality of first vibration signals input from the plurality of first vibration detectors and the second vibration signal input from the second vibration detector, and the detection unit detects the orientation of the seat relative to the fore-and-aft direction of the vehicle body based on the multiple similarities calculated by the first calculation unit.

[0038] According to this aspect, by installing a plurality of first vibration detectors on the left and right sides of the seat and having the detection unit detect the orientation of the seat based on a plurality of similarities, it is possible to improve detection accuracy.

[0039] In the above aspect, the vehicle further includes a signal processing unit that generates a control signal by performing predetermined signal processing on the noise signal as the second vibration signal input from the second vibration detector based on a control coefficient, and a speaker that is installed on or near the seat and outputs the control signal input from the signal processing unit.

[0040] According to this aspect, the noise microphone provided in the active noise control (ANC) can be used as the second vibration detector, thereby making it possible to achieve miniaturization and cost reduction.

[0041] In the above aspect, the device further includes a memory unit that stores a plurality of coefficients corresponding to the seat state, and the memory unit inputs, from among the plurality of coefficients, a coefficient corresponding to the seat state detected by the detection unit to the signal processing unit as the control coefficient.

[0042] According to this aspect, by inputting a coefficient according to the seat state detected by the detection unit as a control coefficient to the signal processing unit, it is possible to improve the noise reduction effect achieved by active noise control.

[0043] In the above aspect, the vibration detection device further includes an updating unit that updates the control coefficient based on an error signal that serves as the first vibration signal input from the first vibration detector.

[0044] According to this aspect, the error microphone provided in the active noise control can be used as the first vibration detector, thereby realizing miniaturization and cost reduction. Furthermore, by updating the control coefficient based on the error signal, it is possible to improve the noise reduction effect of the active noise control.

[0045] A program according to one embodiment of the present disclosure causes a computer as a seat state detection device mounted on a vehicle, the computer comprising at least one first vibration detector installed in at least one seat of the vehicle, detecting vibrations and outputting a first vibration signal, and at least one second vibration detector installed on the vehicle body near the seat, detecting vibrations and outputting a second vibration signal, to function as: a first calculation means for calculating the similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; and a detection means for detecting the seat state, including at least one of the sliding position of the seat in the fore-and-aft direction of the vehicle body, the reclining angle of the seat, and the orientation of the seat relative to the fore-and-aft direction of the vehicle body, based on the similarity calculated by the first calculation means.

[0046] According to this aspect, it is possible to detect the seat state easily and at low cost based on the similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector.

[0047] A seat state detection method according to one embodiment of the present disclosure includes a seat state detection device mounted on a vehicle, the seat state detection device comprising at least one first vibration detector installed in at least one seat of the vehicle, detecting vibrations and outputting a first vibration signal, and at least one second vibration detector installed on the vehicle body near the seat, detecting vibrations and outputting a second vibration signal; the seat state detection device calculates a similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; and, based on the calculated similarity, detects the seat state, including at least one of the sliding position of the seat in the fore-and-aft direction of the vehicle body, the reclining angle of the seat, and the orientation of the seat relative to the fore-and-aft direction of the vehicle body.

[0048] According to this aspect, it is possible to detect the seat state easily and at low cost based on the similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector.

[0049] The present disclosure can also be realized as a program that causes a computer to execute each characteristic configuration included in such an apparatus, or as a system operated by this program. Needless to say, such a computer program can be distributed on a computer-readable non-transitory recording medium such as a CD-ROM or via a communication network such as the Internet.

[0050] (Embodiments of the present disclosure) Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0051] The embodiments described below each represent a preferred specific example of the present disclosure.

[0052] In addition, in the embodiments described below, active noise control (hereinafter abbreviated as "ANC") is shown as an example of a service for occupants seated in seats, but this is not limited to this, and it can be provided to all services and values ​​that can utilize the seat status detected in this disclosure, such as audio control, air conditioning control, lighting control, and airbag control.

[0053] Furthermore, the components, the arrangement and connection of the components, the order of operations, and the like shown in the following embodiments are merely examples and are not intended to limit the present disclosure. The present disclosure is limited only by the scope of the claims.

[0054] Therefore, among the components in the following embodiments, those that are not described in the independent claims that represent the highest concept of the present disclosure are described as constituting more preferred forms, although they are not necessarily necessary to achieve the objectives of the present disclosure.

[0055] (Embodiment 1) The configuration of a seat state detection device according to embodiment 1 will be described. Fig. 1 is a diagram showing the configuration of a seat state detection device according to embodiment 1. The seat state detection device includes similarity calculators 21a and 21b and a seat position determiner 30. The similarity calculators 21a and 21b and the seat position determiner 30 may be functions realized by a CPU executing a program read from a nonvolatile memory such as a ROM, or may be realized by dedicated hardware.

[0056] The seat status detection device in FIG. 1 illustrates an example of seats viewed from above inside a vehicle cabin. Microphones 2a, 2b, 12a, and 12b, which correspond to first vibration detectors, and speakers 3a, 3b, 13a, and 13b are installed in driver's seat 101a, which is located near steering wheel 100, and passenger seat 101b, which is located next to it. Furthermore, microphones 1a and 1b, which correspond to second vibration detectors, are installed in vehicle body 111a (near driver's door window 121a), and microphones 11a and 11b, which correspond to second vibration detectors, are installed in vehicle body 111b (near passenger door window 121b). These microphones and speakers are connected to a noise control filter 40 for reducing vehicle running noise within the vehicle cabin. That is, FIG. 1 illustrates a case in which the seat status detection device is applied to ANC for vehicle running noise, and in this case, the seat status detection device further includes a noise control filter 40.

[0057] Here, microphones 1a, 1b, 11a, and 11b are noise microphones for ANC, and microphones 2a, 2b, 12a, and 12b are error microphones. In noise control filter 40, signal processor 41 processes noise signals indicating road noise detected by noise microphones 1a, 1b, 11a, and 11b so that noise is reduced at the error microphones 2a, 2b, 12a, and 12b positions, and reproduces the processed noise as control sound from speakers 3a, 3b, 13a, and 13b. Then, road noise and control sound interfere with each other at the error microphones 2a, 2b, 12a, and 12b positions, and the resulting residual signal (hereinafter referred to as error signal) is detected by error microphones 2a, 2b, 12a, and 12b. Normally, noise control filter 40 uses adaptive signal processing to update its own control coefficients to minimize this error signal. By repeating this calculation, the error signal is minimized and a control coefficient that reduces road noise is determined. The control coefficients thus obtained are stored in the coefficient memory 42.

[0058] A more detailed explanation will be given using Fig. 2. Fig. 2 shows the inside of noise control filter 40 of Fig. 1.

[0059] 2, noise signals detected by noise microphones 1a, 1b, 11a, and 11b are processed in signal processor 41 with control coefficients within signal processor 41 and output as control signals to speakers 3a, 3b, 13a, and 13b. At the same time, noise signals detected by noise microphones 1a, 1b, 11a, and 11b are processed in transfer characteristic corrector 43 with coefficients within transfer characteristic corrector 43.

[0060] Here, the transfer characteristics from the speakers 3a, 3b, 13a, and 13b to the error microphones 2a, 2b, 12a, and 12b are preset as coefficients in the transfer characteristic corrector 43. The coefficients are set by selecting an appropriate coefficient (a coefficient determined when the seat 101a is located at the solid line position) from a plurality of coefficients pre-stored in the coefficient memory 42 according to the seat position determined (detected) by a seat position determiner 30 (detection unit) described later.

[0061] The coefficients thus set and the noise signals detected by the noise microphones 1 a , 1 b , 11 a , and 11 b are signal-processed by the transfer characteristic corrector 43 , and the output thereof is input to the coefficient updater 44 .

[0062] The coefficient updater 44 updates the control coefficients of the signal processor 41 by adaptive signal processing using the output signal from the transfer characteristic corrector 43 and the error signals from the error microphones 2a, 2b, 12a, and 12b to minimize the error signals. By successively repeating this adaptive signal processing, the error signals are minimized and control coefficients that reduce running noise are determined.

[0063] The control coefficients thus obtained are finally stored in the coefficient memory 42.

[0064] In actual noise microphones, not only the microphones 1a, 1b, 11a, and 11b shown in Fig. 1 but also a number of microphones 1a to 1f are used as shown in Fig. 3. For example, microphones 1a and 1b are installed spaced apart from each other in the longitudinal direction of the vehicle body, and microphones 1a and 1c are installed spaced apart from each other in the vertical direction of the vehicle body. Fig. 3 shows the vicinity of door window 121a when seat 101a is viewed from the side, and naturally, a similar microphone is installed at door window 121b on the passenger side. All of these microphones are used in noise control filter 40.

[0065] Microphones 1a to 1f are installed on vehicle body 111a near seat 101a. In the example of this embodiment, "nearby" means that microphone 2a and microphones 1a and 1b are close enough to detect the same vibration (running noise). In Fig. 3, microphones 1b, 1d, and 1f are installed at the front of the vehicle, while microphones 1a, 1c, and 1e are installed further back, and are arranged so that when seat 101a moves forward or backward, it moves closer to the microphone on either side.

[0066] From here on, how the seat state detection device acts on the noise control filter 40 will be explained using the seat 101a in FIG. 1 as an example.

[0067] In FIG. 1, seat 101a is initially located at the position indicated by the dotted line, and has now moved to the position indicated by the solid line (in the direction closer to steering wheel 100). At this time, microphone 2a inside seat 101a is closest to microphone 1b installed on vehicle body 111a. This is also the case when looking at FIG. 3. Therefore, while the vehicle is moving, noise is detected by microphone 2a and simultaneously by microphone 1b, and the similarity between these two signals (noise signals S2a and S1b) is calculated by similarity calculator 21b. Similarity calculator 21b outputs signal S21b indicating the similarity between noise signals S2a and S1b, and signal S21b is input to seat position determiner 30. As a specific example, the cross-correlation or coherence of the two signals may be calculated.

[0068] Equation (1) shows the cross-correlation function, and for example, if x(t) is the signal detected by microphone 1b and y(t) is the signal detected by microphone 2a, the similarity between the two signals can be calculated. If the similarity is weak, Rxy(τ) approaches 0. Conversely, if the similarity is strong, the value of Rxy(τ) will be large.

[0069]

number

[0070] On the other hand, equation (2) shows the coherence function. Similarly, if x(t) is the signal detected by microphone 1b and y(t) is the signal detected by microphone 2a, Wxy is the cross spectrum of x(t) and y(t), Wxx is the power spectrum of x(t), and Wyy is the power spectrum of y(t), and the coherence function γ 2 indicates the square of the absolute value of the average cross spectrum divided by the average power spectrum of each of x(t) and y(t). If the similarity between the two signals x(t) and y(t) is weak, γ 2 takes a small value (approaching 0), and when the similarity is strong, the value becomes large (approaching 1). Here, the coherence function has a value for each frequency because it is a frequency analysis.

[0071]

number

[0072] Note that the similarity calculation is not limited to cross-correlation or coherence, and may be calculated by calculating the distance between vectors when two signals are regarded as vectors, such as Euclidean distance or Mahalanobis distance. Also, a method of calculating the distance using the power spectrum after frequency analysis as a vector, such as cepstrum distance, may be used.

[0073] In this way, similarity calculator 21b finds the similarity between microphone 1b and microphone 2a at seat 101a indicated by the solid line.

[0074] Similarly, when seat 101a is located at the position indicated by the solid line (i.e., the current time), road noise is detected by microphone 1a and simultaneously detected by microphone 2a, and the similarity between these two signals (noise signals S2a and S1a) is calculated by similarity calculator 21a. Similarity calculator 21a outputs signal S21a indicating the similarity between noise signals S2a and S1a, and signal S21a is input to seat position determiner 30. At this time, microphone 1a and microphone 2a are far apart, so naturally the similarity calculated will be smaller than the similarity calculated using microphones 1b and 2a.

[0075] That is, when the seat position determiner 30 compares the similarities calculated by the similarity calculator 21a and the similarity calculator 21b, it is found that the output signal of the similarity calculator 21b is larger. As a result, the seat position determiner 30 determines that the seat 101a has moved to the current position indicated by the solid line, that is, closer to the handlebars 100. However, the seat position determiner 30 does not necessarily need to compare the two similarities calculated by the similarity calculator 21a and the similarity calculator 21b, and may determine the slide position of the seat 101a based only on the similarity calculated by one of the similarity calculators 21a and 21b.

[0076] Then, in accordance with the result of the determination made by seat position determiner 30 (signal S30), an appropriate coefficient (a coefficient determined when seat 101a is in the position indicated by the solid line) is selected from the coefficients stored in coefficient memory 42 of noise control filter 40 and set in signal processor 41. As a result, a good effect of reducing running noise can be obtained at seat 101a.

[0077] Incidentally, if seat 101a can be freely moved to positions other than the solid and dotted line positions, such as intermediate positions, then by storing the similarity between microphone 2a and microphone 1a at each position, and the similarity between microphone 2a and microphone 1b at each position, it is possible to determine the current position by checking which of the stored similarities the currently calculated similarity is closest to.

[0078] Although this embodiment has been described using seat 101a as an example, it is also possible to obtain a good noise reduction effect in seat 101b by detecting the seat position using microphone 12a, microphone 11a, and microphone 11b.

[0079] Here, in this embodiment, the case where seat position detection is applied to noise control filter 40 has been described. However, by configuring the signal for calculating similarity to be used in common with the signal for noise control, i.e., the signal detected by microphones 1a, 1b, 11a, 11b, 2a, and 12a, there is no need for a new sensor for detecting running noise, which can contribute to miniaturization and cost reduction of the device.

[0080] Furthermore, in this embodiment, two microphones 2a, 2b or microphones 12a, 12b are installed per seat, such as the driver's seat or passenger seat. This is to obtain the effect in at least both ears of the seated occupants, as with ANC. For example, if air conditioning or lighting is to be optimally controlled for each occupant, only one microphone 2a or microphone 12a is required per seat.

[0081] Furthermore, in this embodiment, a microphone is used as a noise detector, but this is not limited to this, and any sensor that can detect signals related to running vibrations such as running noise, such as an acceleration sensor or a vibration sensor, may be used.

[0082] In addition, in this embodiment, the speakers 3a, 3b, 13a, and 13b are configured to be installed near the headrests of the seats, but this is not limitative and they may be installed inside the vehicle, such as in the vehicle bodies 111a and 111b.

[0083] Furthermore, although an automobile is used as an example in this embodiment, the present invention is not limited to this and may be applied to an airplane, a train, or the like.

[0084] (Embodiment 2) The configuration of a seat state detection device according to embodiment 2 will be described. Fig. 4 is a diagram showing the configuration of a seat state detection device according to embodiment 2. The seat state detection device includes similarity calculators 21a and 21b and an absolute angle determiner 51. The similarity calculators 21a and 21b and the absolute angle determiner 51 may be functions realized by a CPU executing a program read from a nonvolatile memory such as a ROM, or may be realized by dedicated hardware.

[0085] As in FIG. 1, the seat state detection device in FIG. 4 illustrates an example of a seat when the interior of a vehicle is viewed from above. While FIG. 1 describes seat position detection, FIG. 4 describes seat reclining angle detection.

[0086] In Figure 4, seat 101a is initially in the position shown by the dotted line, and after reclining adjustment, it is now in the position shown by the solid line. Since it is difficult to see the reclining angle in Figure 4, Figure 5 will also be used to provide additional information.

[0087] In Figure 5, microphones 1a to 1f are installed in the front-to-back direction of the vehicle, as in Figure 3, but what is more noteworthy is that microphones 1a, 1c, and 1e are arranged in a vertical relationship, and similarly, microphones 1b, 1d, and 1f are also arranged in a vertical relationship.

[0088] 5, it can be seen that seat 101a has been reclined from the initial position shown by the dotted line to the current position shown by the solid line. At this time, microphone 2a in seat 101a was initially closest to microphone 1a installed in car body 111a, but as the seat 101a is reclined, the position of microphone 2a has decreased, and now it is closer to microphone 1c.

[0089] 1, in the current reclining position (the position of seat 101a shown by the solid line), the noise from the vehicle while it is moving is detected by microphone 2a and simultaneously by microphone 1a, and the similarity of these two signals (noise signals S2a and S1a) is calculated by similarity calculator 21a. The similarity can be determined by finding the cross-correlation or coherence of these two signals.

[0090] At the same time, the traveling noise is detected by the microphone 2a and the microphone 1c, and the similarity between these two signals (noise signals S2a and S1c) is calculated by the similarity calculator 21b.

[0091] Then, absolute angle determiner 51 (detection unit) compares the similarities calculated by similarity calculator 21a and similarity calculator 21b and finds that the output signal from similarity calculator 21b is currently larger. This causes absolute angle determiner 51 to determine that seat 101a is currently in the position indicated by the solid line, that is, reclined. However, absolute angle determiner 51 does not necessarily need to compare the two similarities calculated by similarity calculator 21a and similarity calculator 21b; it may determine the reclining angle of seat 101a based only on the similarity calculated by one of similarity calculators 21a and 21b.

[0092] Then, in accordance with the result of determination by absolute angle determiner 51 (signal S51), an appropriate coefficient (a coefficient determined when seat 101a is in the position indicated by the solid line) is selected from the coefficients stored in coefficient memory 42 of noise control filter 40 and set in signal processor 41. As a result, a good effect of reducing running noise can be obtained at seat 101a.

[0093] Incidentally, if the reclining angle of seat 101a can be freely adjusted to any intermediate position other than the solid line position and the dotted line position, then by storing the similarity between microphone 2a and microphone 1a at each reclining angle, and the similarity between microphone 2a and microphone 1c for each angle, it is possible to determine the current reclining angle by checking which of the stored similarities the currently calculated similarity is closest to.

[0094] Here, it is naturally conceivable that the reclining angle of seat 101a may be adjusted when it is in the position indicated by the solid line in FIG. 1 (closer to the steering wheel). In this case, microphone 1a or microphone 1c may not necessarily be closest to microphone 2a. In fact, microphone 1b or microphone 1d may be closer. Therefore, it is preferable to calculate the similarity of microphone 2a to each of microphones 1a to 1f in FIG. 3, and determine the sliding position and reclining angle of seat 101a based on which of microphones 1a to 1f has the strongest similarity to microphone 2a.

[0095] Although this embodiment has been described using seat 101a as an example, it is also possible to obtain a good noise reduction effect in seat 101b by detecting the seat position using microphone 12a, microphone 11a, and microphone 11c.

[0096] Here, in this embodiment, the case where reclining angle detection is applied to noise control filter 40 has been described. However, by configuring the signal for calculating similarity to be used in common with the signal for noise control, i.e., the signals detected by microphones 1a, 1c, 11a, 11c, 2a, and 12a, there is no need for a new sensor for detecting running noise, which contributes to miniaturization and cost reduction of the device.

[0097] Furthermore, in this embodiment, two microphones 2a, 2b or microphones 12a, 12b are installed per seat, such as the driver's seat or passenger seat. This is to obtain the effect in at least both ears of the seated occupants, as with ANC. For example, if air conditioning or lighting is to be optimally controlled for each occupant, only one microphone 2a or microphone 12a is required per seat.

[0098] Furthermore, in this embodiment, a microphone is used as a noise detector, but this is not limited to this, and any sensor that can detect signals related to running vibrations such as running noise, such as an acceleration sensor or a vibration sensor, may be used.

[0099] In addition, in this embodiment, the speakers 3a, 3b, 13a, and 13b are configured to be installed near the headrests of the seats, but this is not limitative and they may be installed inside the vehicle, such as in the vehicle bodies 111a and 111b.

[0100] Furthermore, although an automobile is used as an example in this embodiment, the present invention is not limited to this and may be applied to an airplane, a train, or the like.

[0101] Therefore, the case of a train will be explained with reference to Figs. 6 and 7.

[0102] FIG. 6 shows an example of seats when viewed from above inside a carriage of train 500. As shown above, the seats of train 500 are typically configured as two or three seats, such as seats 1D and 1E or seats 1A, 1B, and 1C, and are arranged in a row across an aisle, with multiple rows (10 rows in FIG. 6). The reclining angle of each seat can be adjusted independently. In other words, the carriages of train 500 include multiple seats that are connected and installed in the left-right direction of the car body, and each seat has an independently adjustable reclining angle.

[0103] FIG. 7 is a diagram showing the configuration of a seat state detection device for a vehicle of train 500. In FIG. 7, seats 101a and 101b are integrated, and seats 101a and 101b are equipped with microphones 2b and 12b (first vibration detectors). At the current seat position indicated by the solid line, microphone 2b and microphone 12b are close to each other. The seat state detection device includes similarity calculators 21a to 21c, an absolute angle determiner 51 that detects the absolute reclining angle of seat 101a, and a relative angle determiner 52 that detects the reclining angle of seat 101b relative to seat 101a. Similarity calculators 21a and 21b, absolute angle determiner 51, and relative angle determiner 52 may be functions realized by a CPU executing a program read from a nonvolatile memory such as a ROM, or may be realized by dedicated hardware.

[0104] On the other hand, if seat 101a is initially reclined to the position indicated by the dotted line, microphone 2b and microphone 12b are spaced apart from each other.

[0105] Therefore, similarity calculator 21c (second calculation unit) calculates the similarity between the driving noises (noise signals S2b, S12b) detected by microphone 2b and microphone 12b at each reclining angle. Relative angle determiner 52 compares the similarity (signal S21c for each state) between the initial reclining state shown by the dotted line and the current reclining state shown by the solid line. Relative angle determiner 52 determines that the reclining state shown by the solid line, which has the greatest similarity, is the current reclining position.

[0106] However, relative angle determiner 52 only determines the relative reclining state of seats 101a and 101b, and if both seats are reclined to the same angle as seat 101a, shown by the dotted line, relative angle determiner 52 will output a result that is the same as the current reclining state, shown by the solid line. In other words, if left as is, the truly necessary reclining angle will not be known.

[0107] 4, for seat 101a, the reclining angle of seat 101a relative to car body 111a (or window 121a) is compared using the similarity between microphone 1a and microphone 2a installed on train car body 111a (such as a vehicle panel) and the similarity between microphone 1c and microphone 2a installed on car body 111a, and absolute angle determiner 51 determines the reclining angle of seat 101a as an absolute angle. Then, relative angle determiner 52 determines the relative angle of seat 101b relative to seat 101a, thereby determining the true reclining angle (absolute angle) of seat 101b.

[0108] Then, according to the results of determination by absolute angle determiner 51 and relative angle determiner 52 (signals S51, S52), an appropriate coefficient is selected from the coefficients stored in coefficient memory 42 of noise control filter 40 and set in signal processor 41. As a result, a good effect of reducing running noise can be obtained in seats 101a and 101b.

[0109] In this embodiment, we have described the case where reclining angle detection is applied to noise control filter 40. However, by configuring the signal used to calculate similarity to be used in common with the signal used to control noise, i.e., the signal detected by microphones 1a, 1c, 2a, and 12a, there is no need for a new sensor to detect driving noise, which contributes to miniaturization and cost reduction of the device.

[0110] Furthermore, in this embodiment, two microphones 2a, 2b or microphones 12a, 12b are installed per seat, but this is to obtain the effect in at least both ears of the seated occupant, as with ANC. For example, if air conditioning or lighting is to be optimally controlled for each occupant, only one microphone 2a or microphone 12a is required per seat.

[0111] Furthermore, in this embodiment, a microphone is used as a noise detector, but this is not limited to this, and any sensor that can detect signals related to running vibrations such as running noise, such as an acceleration sensor or a vibration sensor, may be used.

[0112] In addition, in this embodiment, the speakers 3a, 3b, 13a, and 13b are configured to be installed near the headrests of the seats, but this is not limitative and they may be installed inside the vehicle, such as in the vehicle body 111a.

[0113] Furthermore, although a train is used as an example in this embodiment, the present invention is not limited to this and can be applied to a configuration in which a plurality of seats are adjacent to each other, such as an airplane.

[0114] (Embodiment 3) The configuration of a seat state detection device according to embodiment 3 will be described. Fig. 8 is a diagram showing the configuration of a seat state detection device according to embodiment 3. The seat state detection device includes similarity calculators 21a to 21d and seat direction determiners 60a and 60b. The similarity calculators 21a to 21d and the seat direction determiners 60a and 60b may be functions realized by a CPU executing a program read from a nonvolatile memory such as a ROM, or may be realized by dedicated hardware.

[0115] As in Figure 7, the seat state detection device in Figure 8 illustrates an example of a seat when viewed from above inside a train cabin. While Figure 7 explained reclining angle detection, Figure 8 explains detection of the seat orientation (seat direction) relative to the fore-and-aft direction of the car body.

[0116] Unlike cars and airplanes, where the seats are fixed facing forward (towards the steering wheel or cockpit), trains operate on rails, so the direction of travel of the vehicle changes and the seats rotate accordingly. Normally, the seats are adjusted to face directly in the direction of travel of the train, but for example, if there are four passengers in a group, the seats may be facing away from the direction of travel, with two seats facing each other.

[0117] In Figure 8, the currently integrated seats 101a and 101b are assumed to be located in the position indicated by the solid line in the current direction of travel. When viewed from the side of the interior, this appears as indicated by the solid line in Figure 9. Note that the seats in Figure 9 are intentionally shown as being close to the window (although not shown in Figure 9, seat 101b indicated by the solid line is naturally located in front of seat 101a indicated by the solid line).

[0118] In FIG. 9, the microphones 1a to 1f are arranged in the front-rear direction of the vehicle, but when viewed from the seat rotation, they can also be said to be arranged symmetrically with respect to the window 121a.

[0119] As can be seen from FIG. 9, the microphone 2a in the seat 101a is closest to the microphone 1a installed in the train body 111a.

[0120] On the other hand, at this time, microphone 12a in seat 101b is farther away from microphone 1a as can be seen from FIG.

[0121] Therefore, in the current seat direction (the state indicated by the solid line), the noise of a moving train is detected by microphone 2a and simultaneously by microphone 1a, and the similarity of these two signals (noise signals S2a and S1a) is calculated by similarity calculator 21a. The similarity can be determined by finding the cross-correlation or coherence of these two signals.

[0122] At the same time, the traveling noise is detected by the microphone 12a and the microphone 1a, and the similarity between these two signals (noise signals S12a, S1a) is calculated by the similarity calculator 21b.

[0123] Then, when the seat direction determiner 60a (detection unit) compares the similarities calculated by the similarity calculator 21a and the similarity calculator 21b, it is found that the output of the similarity calculator 21a is greater. As a result, the seat direction determiner 60a determines that the seats 101a and 101b are currently facing the direction indicated by the solid line. However, the seat direction determiner 60a does not necessarily need to compare the two similarities calculated by the similarity calculator 21a and the similarity calculator 21b, and may determine the direction of the seats 101a and 101b based only on the similarity calculated by one of the similarity calculators 21a and 21b.

[0124] Meanwhile, similarity calculator 21c calculates the similarity between noise signals S2a and S1b from microphones 2a and 1b, and similarity calculator 21d calculates the similarity between noise signals S12a and S1b from microphones 12a and 1b, but the similarities are low in both cases because the microphones are far apart. As a result, seat direction determiners 60a and 60b determine that microphones 2a and 1a are closest, and the seat direction indicated by the solid line can be determined.

[0125] Then, in accordance with the results of the judgments made by seat direction judgers 60a, 60b (signals S60a, S60b), appropriate coefficients (coefficients found when seats 101a, 101b are in the positions shown by the solid lines) are selected from the coefficients stored in coefficient memory 42 of noise control filter 40 and set in signal processor 41. As a result, a good effect of reducing running noise can be obtained at seats 101a, 101b.

[0126] If seats 101a and 101b are rotated, the state shown by the dotted line will be reached, and in this case microphone 12a and microphone 1b will be closest to each other. In other words, the similarity calculated by similarity calculator 21d will be the largest, and seat direction determiners 60a and 60b can determine that the seats are oriented as shown by the dotted line.

[0127] As a result, even if seats 101a and 101b rotate, by selecting appropriate coefficients (coefficients obtained when seats 101a and 101b are in the dotted line positions) from the coefficients stored in coefficient memory 42 of noise control filter 40 and setting them in signal processor 41, it is possible to obtain a good effect of reducing running noise in seats 101a and 101b.

[0128] Incidentally, in FIG. 8, the example of the integrated seats 101a and 101b has been explained, but in a green car (first class), there may be only one seat, and this will be exemplified in FIG.

[0129] In Figure 10, seat 101a is installed near window 121a. Seat 101a is located in the position indicated by the solid line in the current direction of travel. At this time, microphone 2a inside seat 101a is close to microphone 1a installed in vehicle body 111a, but is far from microphone 1b. On the other hand, microphone 2b inside seat 101a is far from both microphone 1a and microphone 1b.

[0130] Therefore, in the current seat direction (the state indicated by the solid line), the noise of a moving train is detected by microphone 2a and simultaneously by microphone 1a, and the similarity of these two signals (noise signals S2a and S1a) is calculated by similarity calculator 21a. The similarity can be determined by finding the cross-correlation or coherence of these two signals.

[0131] At the same time, the traveling noise is detected by the microphone 2b and the microphone 1a, and the similarity between these two signals (noise signals S2b, S1a) is calculated by the similarity calculator 21b.

[0132] Then, in the seat direction determiner 60a (detection unit), when the similarities calculated by the similarity calculator 21a and the similarity calculator 21b are compared, it is found that the output of the similarity calculator 21a is greater.

[0133] On the other hand, similarity calculator 21c calculates the similarity between noise signal S2a from microphone 2a and noise signal S1b from microphone 1b, and similarity calculator 21d calculates the similarity between noise signal S2b from microphone 2b and noise signal S1b from microphone 1b, but both similarities are small because the microphones are far apart.As a result, the similarity of similarity calculator 21a is the largest.

[0134] As a result, seat direction determiners 60a, 60b determine that seat 101a is facing the current seat direction shown by the solid line. In accordance with the results of the determinations made by seat direction determiners 60a, 60b (signals S60a, S60b), an appropriate coefficient (the coefficient found when seat 101a is in the position shown by the solid line) is selected from the coefficients stored in coefficient memory 42 of noise control filter 40 and set in signal processor 41. As a result, a good effect of reducing running noise can be obtained in seat 101a.

[0135] Next, if seat 101a is rotated, it will reach the state shown by the dotted line, in which case microphone 2b and microphone 1b will be closest. On the other hand, microphone 2a will be farther away from both microphone 1b and microphone 1a. In other words, of the similarity calculators 21a to 21d, the similarity calculated by similarity calculator 21d is the largest, so it can be determined that seat direction determiners 60a and 60b are in the seat direction shown by the dotted line.

[0136] As a result, even if seat 101a rotates, an appropriate coefficient (the coefficient calculated when seat 101a is in the dotted line position) is selected from the coefficients stored in coefficient memory 42 of noise control filter 40 and set in signal processor 41, thereby achieving a good effect of reducing running noise at seat 101a.

[0137] In the present embodiment shown in Figures 8 and 10, the case where seat direction detection is applied to noise control filter 40 has been described. However, by configuring the signal for calculating similarity to be used in common with the signal for noise control, i.e., the signal detected by microphones 1a, 1b, 2a, and 12a, there is no need for a new sensor for detecting running noise, which can contribute to miniaturization and cost reduction of the device.

[0138] Furthermore, in this embodiment, two microphones 2a, 2b or microphones 12a, 12b are installed per seat, but this is to obtain the effect in at least both ears of the seated occupant, as with ANC. For example, if air conditioning or lighting is to be optimally controlled for each occupant, only one microphone 2a or microphone 12a is required per seat.

[0139] Furthermore, although the present embodiment has been described with reference to a seat that is not reclined, it is of course possible to detect the seat direction in the same manner when the seat is reclined.

[0140] For example, when seat 101a is reclined as shown in Figure 7, microphone 2a and microphone 1c are closest to each other, so the similarity calculator can use the output signal of microphone 1c. It is clear from Figure 9 that microphone 1a is installed in the same direction as microphone 1c (to the left of the window in Figure 9) relative to window 121a, and is therefore closer to microphone 2a than microphones 1b, 1d, and 1f installed on the opposite side. Therefore, even if the signal from microphone 2a is used directly without using microphone 1c, the calculated similarity will be greater than that of the microphones installed on the opposite side, allowing the seat direction to be detected correctly.

[0141] Furthermore, in this embodiment, a microphone is used as a noise detector, but this is not limited to this, and any sensor that can detect signals related to running vibrations such as running noise, such as an acceleration sensor or a vibration sensor, may be used.

[0142] In addition, in this embodiment, the speakers 3a, 3b, 13a, and 13b are configured to be installed near the headrests of the seats, but this is not limitative and they may be installed inside the vehicle, such as in the vehicle body 111a. [Industrial Applicability]

[0143] The present disclosure is particularly useful when applied to a vehicle having a seat that is adjustable in at least one of the sliding position in the fore-and-aft direction of the vehicle body, the reclining angle, and the orientation relative to the fore-and-aft direction of the vehicle body. [Explanation of symbols]

[0144] 1a~1f, 2a, 2b, 12a, 12b microphones 3a, 3b, 13a, 13b speakers 21a~21d Similarity Calculator 30 Seat position detector 40 Noise Control Filter 41 Signal processor 42 coefficient memory 44 Coefficient updater 51 Absolute angle judger 52 Relative angle judger 60a, 60b Seat direction detector Seats 101a and 101b

Claims

1. at least one first vibration detector installed in at least one seat of the vehicle, which detects vibration and outputs a first vibration signal; at least one second vibration detector installed on the vehicle body near the seat, detecting vibrations and outputting a second vibration signal; a first calculation unit that calculates a similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; a detection unit that detects a seat state including at least one of a slide position of the seat in a longitudinal direction of the vehicle body, a reclining angle of the seat, and an orientation of the seat with respect to the longitudinal direction of the vehicle body, based on the similarity calculated by the first calculation unit; A seat state detection device comprising:

2. the at least one second vibration detector includes a plurality of second vibration detectors installed spaced apart from each other in the longitudinal direction of the vehicle body, the seat state includes the slide position of the seat in the front-rear direction of the vehicle body, the first calculation unit calculates a plurality of similarities between the first vibration signal and a plurality of second vibration signals input from the plurality of second vibration detectors; The seat state detection device according to claim 1 , wherein the detection unit detects the sliding position of the seat in the longitudinal direction of the vehicle body based on the plurality of similarities calculated by the first calculation unit.

3. the at least one second vibration detector includes a plurality of second vibration detectors installed spaced apart from each other in the vertical direction of the vehicle body, the seat state includes the reclining angle of the seat, the first calculation unit calculates a plurality of similarities between the first vibration signal and a plurality of second vibration signals input from the plurality of second vibration detectors; The seat state detection device according to claim 1 , wherein the detection unit detects the reclining angle of the seat based on the plurality of similarities calculated by the first calculation unit.

4. The at least one seat includes a plurality of seats that are connected and installed in the left-right direction of the vehicle body and whose reclining angles are independently adjustable, the at least one first vibration detector includes a plurality of first vibration detectors installed in the plurality of seats, a second calculation unit that calculates a similarity between the plurality of first vibration signals input from the plurality of first vibration detectors, The seat state detection device according to claim 3 , wherein the detection unit further detects relative reclining angles between the plurality of seats based on the similarity calculated by the second calculation unit.

5. The at least one seat includes a plurality of seats connected together in the left-right direction of the vehicle body, the at least one first vibration detector includes a plurality of first vibration detectors installed in the plurality of seats, the seat state includes the orientation of the seat with respect to a front-rear direction of the vehicle body, the first calculation unit calculates a plurality of similarities between a plurality of first vibration signals input from the plurality of first vibration detectors and the second vibration signal input from the second vibration detector; The seat state detection device according to claim 1 , wherein the detection unit detects the orientations of the plurality of seats with respect to a longitudinal direction of the vehicle body based on the plurality of similarities calculated by the first calculation unit.

6. the at least one first vibration detector includes a plurality of first vibration detectors installed on the left and right sides of the seat, the seat state includes the orientation of the seat with respect to a front-rear direction of the vehicle body, the first calculation unit calculates a plurality of similarities between a plurality of first vibration signals input from the plurality of first vibration detectors and the second vibration signal input from the second vibration detector; The seat state detection device according to claim 1 , wherein the detection unit detects the orientation of the seat with respect to a longitudinal direction of the vehicle body based on the plurality of similarities calculated by the first calculation unit.

7. a signal processing unit that performs predetermined signal processing on a noise signal serving as the second vibration signal input from the second vibration detector based on a control coefficient to generate a control signal; a speaker that is installed at or near the seat and outputs the control signal input from the signal processing unit; The seat state detection device according to any one of claims 1 to 6, further comprising:

8. Further, a storage unit is provided for storing a plurality of coefficients according to seat states, The seat state detection device according to claim 7 , wherein the storage unit inputs, as the control coefficient, a coefficient corresponding to the seat state detected by the detection unit, out of the plurality of coefficients to the signal processing unit.

9. 9. The seat state detection device according to claim 7, further comprising an update unit that updates the control coefficient based on an error signal as the first vibration signal input from the first vibration detector.

10. at least one first vibration detector installed in at least one seat of the vehicle, which detects vibration and outputs a first vibration signal; at least one second vibration detector installed on the vehicle body near the seat, detecting vibrations and outputting a second vibration signal; a computer as a seat state detection device mounted on the vehicle, a first calculation means for calculating a similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; a detection means for detecting a seat state including at least one of a slide position of the seat in a longitudinal direction of the vehicle body, a reclining angle of the seat, and an orientation of the seat with respect to the longitudinal direction of the vehicle body, based on the similarity calculated by the first calculation means; A program to function as a

11. at least one first vibration detector installed in at least one seat of the vehicle, which detects vibration and outputs a first vibration signal; at least one second vibration detector installed on the vehicle body near the seat, detecting vibrations and outputting a second vibration signal; The seat state detection device mounted on the vehicle includes: calculating a similarity between the first vibration signal input from the first vibration detector and the second vibration signal input from the second vibration detector; A seat state detection method that detects a seat state including at least one of the sliding position of the seat in the fore-and-aft direction of the vehicle body, the reclining angle of the seat, and the orientation of the seat relative to the fore-and-aft direction of the vehicle body based on the calculated similarity.

Images