JP2018165070A - Occupant state estimation device and method of estimating occupant state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate ride comfort of an occupant in a vehicle by a simple structure.SOLUTION: An occupant state estimation device 100 obtains a vehicle behavior signal from a vehicle behavior sensor 10 that is fixed and set on a vehicle to detect movements of the vehicle and/or inclination of a vehicle body. The vehicle behavior signal includes vehicle behaviors indicating movements of the vehicle and/or inclination of the vehicle body. The occupant state estimation device obtains a gravity center movement control signal including movements of the gravity center of an occupant from a gravity center movement control sensor 20 that is configured to detect movements of the gravity center of at least one occupant in the vehicle. Then, for example, a fluctuation calculation part 101 calculates fluctuations on the basis of time-sequence data of differences between the vehicle behavior signal and the gravity center movement control signal, and a comfort/discomfort estimation part 102 estimates on the basis of the calculated fluctuations whether the occupant feels comfortable on the vehicle behaviors.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a state of a driver and / or a passenger of a traveling vehicle, and in particular, an occupant state estimation for estimating a ride comfort of a vehicle (that is, comfort (including discomfort)) felt by the vehicle occupant. The present invention relates to a device and an occupant state estimation method. In this specification, a driver and / or a passenger are referred to as an occupant.

  Conventionally, as a technique for determining the state of a driver driving a vehicle, for example, a technique disclosed in Patent Document 1 below is known. In Patent Literature 1, four load sensors that detect a load acting on a seat on which a driver is seated, a feature amount output device that outputs a feature amount based on a detection result by the load sensor, and a driving state of the driver based on the feature amount are disclosed. A state determination device including a determination device is disclosed.

JP 2012-166579 A (paragraph 0017, FIG. 1)

  According to the technique disclosed in Patent Document 1, the driving state of the driver can be determined with a simple configuration, but the behavior of the vehicle is not taken into consideration and the driver's state can be accurately specified. Not necessarily.

  In view of the above problems, the present invention provides an occupant state estimation device and an occupant state estimation method capable of estimating the state of a vehicle occupant (the ride comfort of the vehicle felt by the vehicle occupant) with a simple configuration. With the goal.

In order to achieve the above object, an occupant state estimating device of the present invention is an occupant state estimating device that estimates the state of an occupant of a vehicle,
A vehicle behavior signal including a vehicle behavior indicating the motion of the vehicle and / or the tilt of the vehicle body is acquired from a vehicle behavior sensor that detects the motion of the vehicle and / or the tilt of the vehicle body fixedly installed on the vehicle. A vehicle behavior signal acquisition unit,
A center-of-gravity braking signal acquisition unit that acquires a center-of-gravity braking signal including movement of the center of gravity of the occupant from a center-of-gravity braking sensor that detects the movement of the center of gravity of at least one occupant in the vehicle;
An occupant state estimation unit that estimates whether the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior based on the vehicle behavior signal and the gravity center braking signal;
Have.

In order to achieve the above object, an occupant state estimation method of the present invention is an occupant state estimation method for estimating the state of an occupant of a vehicle,
A vehicle behavior signal including a vehicle behavior indicating the motion of the vehicle and / or the tilt of the vehicle body is acquired from a vehicle behavior sensor that detects the motion of the vehicle and / or the tilt of the vehicle body fixedly installed on the vehicle. Vehicle behavior signal acquisition step,
A center-of-gravity braking signal acquisition step of acquiring a center-of-gravity braking signal including a movement of the center of gravity of the occupant from a center-of-gravity braking sensor that detects the movement of the center of gravity of at least one occupant in the vehicle;
An occupant state estimation step for estimating whether the occupant feels good riding comfort of the vehicle with respect to the vehicle behavior based on the vehicle behavior signal and the gravity center braking signal;
Have.

  The present invention has the above-described configuration and has an effect of estimating the state of a vehicle occupant with a simple configuration. In addition, the present invention has an effect of estimating the state of a vehicle occupant with a simple configuration without using a physiological monitoring device such as an electrocardiograph.

It is a figure which shows typically the basic concept which concerns on this invention. It is a block diagram which shows an example of the apparatus structure in the 1st Embodiment of this invention. In the first embodiment of the present invention, an example of a graph in which a wave obtained from the difference between the vehicle behavior signal and the gravity center braking signal is decomposed into a plurality of waves and the spectrum intensity of each frequency component is plotted on the logarithmic axis FIG. It is a block diagram which shows an example of the apparatus structure in the 2nd Embodiment of this invention. It is a figure which shows typically an example of the process using the method of the nonlinear dynamics performed in the 2nd Embodiment of this invention. It is a block diagram which shows an example of the apparatus structure in the 3rd Embodiment of this invention. It is a block diagram which shows an example of the apparatus structure in the 4th Embodiment of this invention. It is a graph which shows an example of the motion correlation (active center-of-gravity braking) with the vehicle behavior and center-of-gravity braking concerning the present invention. It is a graph which shows an example of the motion correlation (passive center-of-gravity braking) with the vehicle behavior and center-of-gravity braking concerning the present invention. It is a graph which shows an example of the motion correlation (deadman state) with the vehicle behavior and gravity center braking concerning the present invention.

  Hereinafter, the basic concept of the present invention and the first to fourth embodiments of the present invention will be described with reference to the drawings.

<Basic concept>
First, the basic concept of the present invention will be described with reference to FIG. The vehicle occupant controls the movement of the center of gravity of the body according to the vehicle behavior (hereinafter referred to as center of gravity braking) in order to maintain an appropriate seating state with respect to the movement of the vehicle while traveling (hereinafter referred to as vehicle behavior) Is described). The vehicle behavior and gravity center braking will be described later. That is, as schematically shown in FIG. 1, the vehicle behavior affects the occupant's center of gravity braking. The basic concept of the present invention is to focus on the fact that the centroid braking of the occupant working according to the vehicle behavior of the running vehicle has a correlation with the riding comfort (good or bad) of the occupant, and the vehicle behavior and the occupant center of gravity braking. Is to evaluate the ride comfort of passengers from these observation results. In addition, although the motor vehicle is illustrated in FIG. 1 as an example of a vehicle, the vehicle in this invention is not limited only to a motor vehicle. Vehicles in the present invention include vehicles such as automobiles, motorcycles, bicycles, and trains, and are defined to include all vehicles on which people such as ships and airplanes can ride.

  An occupant state estimation device according to an embodiment of the present invention includes a sensor for observing vehicle behavior and a sensor for observing occupant center of gravity braking, and how occupant center of gravity braking works according to vehicle behavior. From the detection result, how the passenger feels the riding comfort is evaluated as the comfort level / discomfort level. In particular, when the occupant (driver) is performing manual driving, it is important to evaluate whether the driver is driving comfortably. In addition, during automatic driving, it is important to evaluate whether or not the automatic driving system is driving that causes discomfort to the passengers.

  The vehicle behavior is, for example, a vehicle caused by centrifugal force or inertial force, road surface conditions (uphill, downhill, left-right slope, bumpy, etc.) that are applied during acceleration / deceleration, deceleration, turning, lane change, etc. This refers to vehicle movement that causes the center of gravity braking of the passenger. As a sensor for observing the vehicle behavior, an acceleration sensor and / or a three-axis gyro sensor installed in a fixed state on the vehicle side can be used. For example, a sensor built in the car navigation device, a sensor built in a drive recorder or a digital tachograph may be used, and a dedicated sensor for realizing the operation according to the present invention may be provided. Furthermore, since devices such as smartphones and smart watches are equipped with acceleration sensors and 3-axis gyro sensors and are always in operation, these devices can be placed in the vehicle and used as sensors to observe vehicle behavior. May be. The sensor is not limited to the above sensors as long as the vehicle behavior can be observed.

  The occupant's center-of-gravity braking is a body control exercise in which the occupant attempts to stabilize the center of gravity of the body in accordance with the vehicle behavior, and refers to center-of-gravity braking caused by the vehicle behavior. As a sensor for observing the occupant's center of gravity braking, a seat pressure sensor (single point or multiple point load sensor) may be used. Based on the image obtained by the in-vehicle camera attached to the drive recorder, etc. The position of the center of gravity of the occupant may be estimated using capture or image analysis technology. Furthermore, an occupant may wear a device such as a smartphone or a smart watch on which an acceleration sensor and a three-axis gyro sensor are mounted, and may be used as a sensor for observing braking of the center of gravity. The sensors are not limited to the above sensors as long as they can observe the occupant's center of gravity braking.

  There are active center-of-gravity braking and passive center-of-gravity braking for occupant center-of-gravity braking. In active center-of-gravity braking, the occupant predicts the curvature of the road ahead and the situation in which the vehicle accelerates, and then performs center-of-gravity braking in advance (in other words, an act of foreseeing the movement of the vehicle and setting up the body). The center of gravity is braked so that it does not occur. In other words, active center-of-gravity braking refers to a motion of braking the center of gravity by tilting the body inward in advance when centrifugal force is expected to act as a vehicle behavior, such as when entering a corner. As shown in FIG. 8, the gravity center braking tends to occur before the vehicle behavior. FIG. 8 is a graph in which the vertical axis represents acceleration and the horizontal axis represents time. The vehicle behavior is represented by a solid line and the center of gravity braking is represented by a dotted line. As shown in FIG. 8, in active center-of-gravity braking, center-of-gravity braking with the same level of force (acceleration) in the repulsion direction is performed prior to vehicle behavior.

  On the other hand, in passive center-of-gravity braking, the occupant is shaken according to vehicle behavior such as acceleration / deceleration of the vehicle and centrifugal force of the curve, and center-of-gravity braking is performed on this. In other words, passive center-of-gravity braking is, for example, a motion of center-of-gravity braking to return the body (center of gravity) swung by vehicle behavior to its original seating state (center of gravity is neutral), and the motion correlation with vehicle behavior is As shown in FIG. 9, gravity center braking tends to occur with a delay from the vehicle behavior. FIG. 9 is a graph in which the vertical axis represents acceleration and the horizontal axis represents time. The vehicle behavior is represented by a solid line, and the center of gravity braking is represented by a dotted line. As shown in FIG. 9, in passive center-of-gravity braking, center-of-gravity braking with the same force (acceleration) in the repulsion direction is performed following the vehicle behavior.

  In addition, in an unresponsive state where the occupant does not perform center-of-gravity braking (such as a deadman state in this specification), such as when the person is stunned, active center-of-gravity braking or passive center-of-gravity Braking is not performed, and a center of gravity motion swung by the turning motion or braking motion of the vehicle occurs. Specifically, as shown in FIG. 10, after the body is swung by the vehicle behavior, the operation of returning to the original seating state (the state where the center of gravity is neutral) is not performed. In FIG. 10, the vertical axis represents acceleration and the horizontal axis represents time. The vehicle behavior is represented by a solid line, and the center of gravity braking is represented by a dotted line. As shown in FIG. 10, in the deadman state, the occupant has lost consciousness, and thus the force (acceleration) does not enter after being swung by the vehicle behavior.

  In the present invention, any rider who can observe center-of-gravity braking can estimate the ride comfort of the rider regardless of the seating position in the vehicle. That is, according to the present invention, it is possible to estimate the ride comfort of not only the driver seated in the driver's seat but also the passenger seated in the passenger seat, the rear seat, and the like.

<First Embodiment>
Next, a first embodiment of the present invention will be described. FIG. 2 is a block diagram showing an example of a device configuration according to the first embodiment of the present invention. FIG. 2 shows an occupant state estimation device 100, a vehicle behavior sensor 10, and a gravity center braking sensor 20.

  The vehicle behavior sensor 10 is a sensor for observing the vehicle behavior, and as described above, a sensor installed in an existing apparatus or a sensor installed for the present invention can be used. The vehicle behavior sensor 10 observes the vehicle behavior, and includes a signal including the observation result (for example, a signal including acceleration detected by the acceleration sensor and angular velocity detected by the three-axis gyro sensor: hereinafter referred to as a vehicle behavior signal) Output).

  The center-of-gravity braking sensor 20 is a sensor that observes the center-of-gravity braking of an occupant, and as described above, a sensor installed in an existing device or a sensor installed for the present invention can be used. The center-of-gravity braking sensor 20 observes the occupant's center-of-gravity braking, and includes a signal including the observation result (for example, a signal including acceleration detected by an acceleration sensor or angular velocity detected by a three-axis gyro sensor: Output).

  The occupant state estimation device 100 acquires the vehicle behavior signal output from the vehicle behavior sensor 10 and the center of gravity braking signal output from the center of gravity braking sensor 20 (vehicle behavior signal acquisition unit, center of gravity braking signal acquisition unit), and these It has a function of estimating how the passenger feels the ride comfort based on the fluctuation of the wave (time-series data) obtained by the difference between the signals and outputting the estimation result as the comfort level / discomfort level. The occupant state estimation device 100 includes a fluctuation calculation unit 101 and a comfort / discomfort level estimation unit 102.

  The fluctuation calculation unit 101 has a function of calculating the difference between the vehicle behavior signal and the gravity center braking signal and calculating the fluctuation of the wave represented by the difference. The difference between the vehicle behavior signal and the center of gravity braking signal may be, for example, the difference between the vehicle behavior signal and the center of gravity braking signal at the same time. In this case, in the example shown in FIGS. Difference (difference in the vertical axis direction) is calculated. Alternatively, the difference between the vehicle behavior signal and the center-of-gravity braking signal may be, for example, a delay time (or preceding time) of the center-of-gravity braking signal with respect to the vehicle behavior signal. In this case, in the example illustrated in FIGS. The difference in time (difference in the horizontal axis direction) at which similar acceleration appears is calculated. In any case, a wave along the time axis is obtained by calculating the difference between the vehicle behavior signal and the gravity center braking signal.

  Further, the fluctuation calculation unit 101 has a function of calculating a wave fluctuation obtained from the difference between the vehicle behavior signal and the gravity center braking signal, for example, using a conventionally known fluctuation calculation method. The fluctuation is obtained by calculating the correlation between the spectral intensity and the frequency. Specifically, the wave obtained from the difference between the vehicle behavior signal and the center-of-gravity braking signal is decomposed into a plurality of waves having different frequencies by fast Fourier transform or the like, and the correlation of the spectrum intensity of each frequency component is calculated.

  FIG. 3 shows an example of a graph in which the wave obtained from the difference between the vehicle behavior signal and the gravity center braking signal is decomposed into a plurality of waves, and the spectrum intensity of each frequency component is plotted on the logarithmic axis. In FIG. 3, the vertical axis represents the spectral intensity, and the horizontal axis represents the frequency. When the slope of the approximate straight line obtained from the plotted points is −1, the state is 1 / f fluctuation. The fluctuation calculation unit 101 can output the slope value of the approximate line as a value representing fluctuation.

  The comfort level / discomfort level estimation unit 102 has a function of estimating the state of the occupant (occupant state estimation unit), and more specifically, based on a value representing the fluctuation output from the fluctuation calculation unit 101. It has a function (ride comfort estimation unit) that estimates ride comfort and outputs evaluation values of comfort and discomfort. For example, the comfort level / discomfort level estimation unit 102 determines that the value representing the fluctuation is a value close to −1 (eg, within a predetermined range (for example, −0.8 to −1.2)). On the other hand, it is estimated that the ride comfort of the occupant is comfortable (a comfortable ride). If the value representing the fluctuation is outside the predetermined range, the ride comfort of the occupant is estimated to be uncomfortable. Is output.

  The fluctuation calculated by the fluctuation calculation unit 101 is derived from the movement of the center of gravity braking of the occupant with respect to the vehicle behavior, and whether the movement according to the movement of the vehicle is stably and continuously performed (that is, the vehicle It can be regarded as an index indicating whether the movement can be matched with a good rhythm. Therefore, just as it is generally known that 1 / f fluctuation is a comfortable state, in the case of 1 / f fluctuation, it is estimated that the occupant is in a comfortable state. Can do. However, the value or range for estimating that the ride comfort of the occupant is comfortable is not limited to the above value (the value indicating fluctuation is close to -1) or the range, and an appropriate value or range is appropriately selected. It is possible to set. Further, the estimation result may be output by classifying into a plurality of categories such as comfortable, slightly comfortable, neither comfortable, slightly uncomfortable, or uncomfortable. Also, when the fluctuation value is extremely different from the normal state in which the occupant is performing center-of-gravity braking (for example, close to 1 / f2 fluctuation indicating a very monotonous and predictable state), The passenger may be estimated to be in a deadman state.

  As described above, in the first embodiment of the present invention, the difference between the vehicle behavior signal representing the movement of the vehicle and the gravity center braking signal representing the movement of the center of gravity of the occupant is calculated, and the fluctuation of the wave represented by the difference is calculated. It is possible to calculate and estimate the ride comfort of the occupant based on the fluctuation value.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 4 is a block diagram showing an example of a device configuration according to the second embodiment of the present invention. FIG. 4 shows an occupant state estimation device 200, a vehicle behavior sensor 10, and a gravity center braking sensor 20. Note that the vehicle behavior sensor 10 and the center-of-gravity braking sensor 20 are the same as those in the first embodiment described above, and a description thereof is omitted here.

  The occupant state estimation device 200 acquires the vehicle behavior signal output from the vehicle behavior sensor 10 and the center of gravity braking signal output from the center of gravity braking sensor 20 (vehicle behavior signal acquisition unit, center of gravity braking signal acquisition unit), and these The Lyapunov exponent is calculated from the signal difference using a nonlinear analysis technique, and how the passenger feels the riding comfort is estimated based on the fluctuations of the Lyapunov exponent wave. As an output function. The occupant state estimation device 100 includes a nonlinear analysis unit 201, a fluctuation calculation unit 202, and a comfort / discomfort level estimation unit 203.

  The non-linear analysis unit 201 acquires the vehicle behavior signal output from the vehicle behavior sensor 10 and the gravity center braking signal output from the gravity center braking sensor 20 in millisecond order (millisecond unit). The difference between the braking signal and the nonlinear analysis method are used to generate an attractor of the difference between the vehicle behavior signal and the center of gravity braking signal (or part of the difference), and the calculated result (the difference is It has a function of performing fluctuation analysis processing on the attracted one) and calculating a Lyapunov exponent related to the difference.

  The non-linear analysis process performed in the non-linear analysis unit 201 is schematically shown in FIG. The nonlinear analysis unit 201 acquires the generated attractor, analyzes the stability tendency with respect to the past attractor matrix, calculates the current Lyapunov exponent, and accumulates the calculated Lyapunov exponent transition (time-series data) as a log (logging) ) For example, by acquiring the attractor (trajectory) of a local trend (local trend) within a minute window while shifting the range of a predetermined minute window (time width τ), a plurality of attractors (attractor matrices) are obtained. It is possible to calculate the Lyapunov exponent from a plurality of attractors (attractor matrices) obtained in this way. At this time, although only one Lyapunov exponent is calculated, the Lyapunov exponent time-series data (time-sequentially different) is obtained by shifting a window (metawindow) including a plurality of predetermined minute windows (time width τ). A plurality of Lyapunov indices) can be obtained. Further, the Lyapunov exponent may be calculated at an arbitrary cycle, for example, at a cycle of 0.5 seconds. Note that the calculation method of the fluctuation analysis process in the second embodiment of the present invention is not limited to the one shown in FIG. Various studies have been conducted on the technique of nonlinear analysis, and any analysis technique established now and in the future can be applied to the present invention (for example, the complex system analysis tool that has come here, http: //www.ieice.org/cs/csbn/program/papers/04_1_miao.pdf)

  The fluctuation calculation unit 202 has a function of calculating, for example, a wave fluctuation represented by the time series data of the Lyapunov exponent obtained from the difference between the vehicle behavior signal and the gravity center braking signal using a conventionally known fluctuation calculation method. Have. Note that the fluctuation calculation unit 101 according to the first embodiment described above calculates the fluctuation of the wave represented by the difference between the vehicle behavior signal and the gravity center braking signal (that is, the difference between the vehicle behavior signal and the raw data of the gravity center braking signal). It is configured to On the other hand, the fluctuation calculation unit 202 in the second embodiment uses a nonlinear analysis method for the difference between the vehicle behavior signal and the gravity center braking signal (that is, the difference between the vehicle behavior signal and the raw data of the gravity center braking signal). The first embodiment is different from the first embodiment in that the Lyapunov exponent is used to calculate the fluctuation of the wave represented by the time series data of the Lyapunov exponent that is the calculation result. However, although the data to be handled is different, the fluctuation calculation unit 202 in the second embodiment also calculates the correlation between the spectral intensities of each frequency component by decomposing into a plurality of waves having different frequencies by fast Fourier transform or the like. It is possible to output the slope value of the approximate straight line as shown in FIG. 3 as a value representing fluctuation. Therefore, since the same processing as that of the fluctuation calculation unit 101 in the first embodiment described above is performed, the description of the fluctuation calculation processing in the fluctuation calculation unit 202 is omitted here.

  The comfort level / discomfort level estimation unit 203 has the same function as the comfort level / discomfort level estimation unit 102 in the first embodiment described above, and is based on a value representing the fluctuation output from the fluctuation calculation unit 101. It has a function of estimating the ride comfort of the occupant and outputting an evaluation value of comfort / discomfort. Therefore, since the same processing as the comfort level / discomfort level estimation unit 102 in the first embodiment described above is performed, description of the processing in the comfort level / discomfort level estimation unit 203 is omitted here.

  As described above, in the second embodiment of the present invention, the difference between the vehicle behavior signal representing the movement of the vehicle and the center of gravity braking signal representing the movement of the center of gravity of the occupant is calculated, and the nonlinear analysis method is calculated from the difference. It is possible to calculate the Lyapunov exponent and to estimate the ride comfort of the occupant based on the fluctuation of the Lyapunov exponent wave.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. FIG. 6 is a block diagram showing an example of a device configuration according to the third embodiment of the present invention. FIG. 6 shows an occupant state estimation device 300, a vehicle behavior sensor 10, and a gravity center braking sensor 20. Note that the vehicle behavior sensor 10 and the center-of-gravity braking sensor 20 are the same as those in the first embodiment described above, and a description thereof is omitted here.

  The occupant state estimation device 300 acquires the vehicle behavior signal output from the vehicle behavior sensor 10 and the center of gravity braking signal output from the center of gravity braking sensor 20 (vehicle behavior signal acquisition unit, center of gravity braking signal acquisition unit). The Lyapunov exponent is calculated from the difference between the two signals using a nonlinear analysis method, and the passenger is given a feeling of riding comfort by performing processing related to DFA (Detrended Fluctuation Analysis) analysis on this Lyapunov exponent. It has a function of estimating whether it is felt and outputting the estimation result as comfort level / discomfort level. The occupant state estimation device 300 includes a nonlinear analysis unit 301, a DFA analysis unit 302, and a comfort / discomfort level estimation unit 303.

  The nonlinear analysis unit 301 has a function of calculating a Lyapunov exponent related to a difference between the vehicle behavior signal output from the vehicle behavior sensor 10 and the gravity center braking signal output from the gravity center braking sensor 20 using a nonlinear analysis technique. Have. The nonlinear analysis unit 301 performs the same processing as the nonlinear analysis unit 201 in the second embodiment described above, and a description thereof is omitted here.

  The DFA analysis unit 302 performs a DFA analysis based on the wave represented by the time series data of the Lyapunov exponent obtained from the difference between the vehicle behavior signal and the gravity center braking signal, and outputs the DFA analysis result (scaling exponent α) Have Note that DFA analysis is a technique for analyzing long-term correlation characteristics of non-stationary time-series data, and since it is a widely known technique, detailed description thereof is omitted here. New time series data created by integrating the input data is divided into boxes of length n, and the local trend is calculated by calculating an approximate straight line by the least square method in each box, and the trend is removed from the signal. A value (F (n)) obtained by averaging the variances is calculated. F (n) determined by this DFA analysis can be expressed by F (n) ∝nα and is characterized by a scaling index α.

  The inventor of the present invention has found that the scaling index α obtained by the DFA analysis is useful for estimating passenger comfort / discomfort. For example, when a predetermined threshold value is set and the scaling index α is greater than or equal to the predetermined threshold value, it can be estimated that the occupant is comfortable, and when the scaling index α is less than the predetermined threshold value, the occupant is uncomfortable. Can be estimated.

  The comfort level / discomfort level estimation unit 303 has a function of estimating the occupant state (occupant state estimation unit), and more specifically, the DFA analysis result (value of the scaling index α) output from the DFA analysis unit 302. ) To estimate the ride comfort of the occupant and output an evaluation value of comfort / discomfort (ride comfort estimation unit). For example, the comfort / discomfort estimation unit 303 compares the value of the scaling index α output from the DFA analysis unit 302 with a predetermined threshold set as a reference for estimating the comfort / discomfort. When the scaling index α is greater than or equal to a predetermined threshold value, it is estimated that the ride comfort of the occupant is comfortable (a comfortable ride). On the other hand, when the scaling index α is less than the predetermined threshold value, the ride comfort of the occupant is uncomfortable. And the estimation result is output. Here, as an example, one threshold value is used as a boundary value, and it is classified into two categories, a comfortable state and an unpleasant state. However, the value set as the threshold value, the number of threshold values, and the number of categories to be classified are appropriately determined. It is possible to set. Further, when the DFA analysis result is extremely different from the normal state in which the occupant performs center-of-gravity braking (for example, when the scaling index α is extremely low), the occupant is in the deadman state. It may be estimated that there is.

  As described above, in the third embodiment of the present invention, the Lyapunov exponent is calculated from the difference between the vehicle behavior signal representing the movement of the vehicle and the center of gravity braking signal representing the movement of the center of gravity of the occupant using the nonlinear analysis technique. Furthermore, it is possible to perform a process related to the DFA analysis on the Lyapunov exponent and estimate the ride comfort of the occupant based on the DFA analysis result.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. FIG. 7 is a block diagram showing an example of a device configuration according to the fourth embodiment of the present invention. FIG. 7 shows an occupant state estimation device 400, a vehicle behavior sensor 10, and a gravity center braking sensor 20. Note that the vehicle behavior sensor 10 and the center-of-gravity braking sensor 20 are the same as those in the first embodiment described above, and a description thereof is omitted here.

  The occupant state estimation device 400 acquires the vehicle behavior signal output from the vehicle behavior sensor 10 and the gravity center braking signal output from the gravity center braking sensor 20 (vehicle behavior signal acquisition unit, center of gravity braking signal acquisition unit), and the vehicle Based on the behavior signal and the center-of-gravity braking signal, it is determined whether the occupant is performing active center-of-gravity braking or passive center-of-gravity braking, and how the occupant feels riding comfort based on the determination result. It has a function of estimating and outputting the estimation result as comfort level and discomfort level. The occupant state estimation device 100 includes a center-of-gravity braking state determination unit 401 and a comfort / discomfort level estimation unit 402.

  The center-of-gravity braking state determination unit 401 acquires the vehicle behavior signal output from the vehicle behavior sensor 10 and the center-of-gravity braking signal output from the center-of-gravity braking sensor 20, and the center of gravity braking in which the occupant is active based on these signals. Has a function of determining whether or not passive center-of-gravity braking is being performed. As described above, for example, in the active center-of-gravity braking shown in FIG. 8, the vehicle behavior that will occur is predicted, and the center of gravity braking of the occupant is performed prior to the vehicle behavior. In the passive center-of-gravity braking shown in FIG. 9, contrary to the active center-of-gravity braking, after the vehicle behavior occurs, the center-of-occupant braking is performed following the vehicle behavior. That is, the center-of-gravity braking state determination unit 401 performs active center-of-gravity braking when the occupant's center-of-gravity braking indicated by the center-of-gravity braking signal is performed prior to the vehicle behavior indicated by the vehicle behavior signal. If it is determined that the operation is delayed, it can be determined that passive gravity center braking is being performed. Further, when the occupant's center-of-gravity braking is in the deadman state as shown in FIG. 10, for example, the occupant may be determined to be in the deadman state.

  Note that the center-of-gravity braking state determination unit 401 indicates that, for example, the center of gravity braking of the occupant is performed in advance of the vehicle behavior, or the center of gravity braking of the occupant is performed after the vehicle behavior is delayed. May be determined that active center-of-gravity braking or passive center-of-gravity braking is being performed.

  The comfort level / discomfort level estimation unit 402 has a function of estimating the occupant state (occupant state estimation unit). More specifically, the determination result (active center of gravity braking) output from the gravity center braking state determination unit 401 Or a function (riding comfort estimation unit) for estimating the ride comfort of the occupant and outputting an evaluation value of comfort / discomfort.

  As described above, in active center-of-gravity braking, the vehicle behavior that will occur in the future is predicted, and the center of gravity braking of the occupant is performed prior to the vehicle behavior. For example, when starting from a signal waiting state or turning a curve, passengers as well as passengers foresee vehicle behavior that will occur in the near future, and naturally perform center of gravity braking according to the predicted vehicle behavior. Going (unconsciously dressed up). Thus, when the motion according to the motion of the vehicle is stably and continuously performed, it can be estimated that the occupant is in a comfortable state.

  On the other hand, in passive center-of-gravity braking, contrary to active center-of-gravity braking, after vehicle behavior occurs, center-of-gravity braking is performed following the vehicle behavior. For example, in the case of sudden acceleration / deceleration (rapid start or braking), sudden turning due to approaching another vehicle or obstacle, sudden lane change, etc., the occupant cannot predict the vehicle behavior and It will be in a state to be swayed by the movement of. Thus, when the movement according to the movement of the vehicle is not stably and continuously performed, it can be estimated that the occupant is in an uncomfortable state.

  For example, when the determination result output from the center-of-gravity braking state determination unit 401 indicates that the center-of-gravity braking state determination unit 401 indicates active center-of-gravity braking, the ride comfort level of the passenger is comfortable (feeling comfortable for the vehicle When the determination result output from the gravity center braking state determination unit 401 indicates that the vehicle is in a passive state of gravity braking, it is estimated that the ride comfort of the occupant is uncomfortable, and the estimation Output the result. Here, as an example, it is classified into two categories, a comfortable state and an unpleasant state, but for example, depending on the number of times or time of active center of gravity braking or passive center of gravity braking, it is comfortable or slightly comfortable It is possible to classify them into a plurality of categories such as slightly uncomfortable or uncomfortable, and output the estimation result. Further, when the determination result output from the gravity center braking state determination unit 401 indicates that it is in the deadman state, the occupant may be estimated to be in the deadman state.

  As described above, in the fourth embodiment of the present invention, whether the occupant's center-of-gravity braking is an active center-of-gravity braking by comparing the vehicle behavior signal indicating the movement of the vehicle and the center-of-gravity braking signal indicating the movement of the center of gravity of the occupant. It is possible to determine whether it is passive center-of-gravity braking, and to estimate the ride comfort of the occupant based on the determination result.

The estimation result output by the occupant state estimation device in the first to fourth embodiments described above indicates that the ride comfort of the occupant is comfortable (shows that the occupant feels comfortably with respect to the vehicle behavior). Information) or information indicating that the ride comfort of the occupant is uncomfortable (information indicating that the occupant feels uncomfortable with respect to the vehicle behavior). Furthermore, the estimation result may include information indicating that the occupant is in a deadman state. This estimation result can be used for various purposes.

  For example, vehicle travel control or drive control may be performed based on the estimation result output by the occupant state estimation device in the first to fourth embodiments. When it is estimated that the occupant is in a comfortable state, control is performed so as to maintain or further improve the traveling state, and when it is estimated that the occupant is in an uncomfortable state, the traveling state is changed. Control may be performed to improve. Specifically, when manual driving is being performed, the coefficient of the suspension (hardness) and torque (power) during winding is adjusted to improve the comfort state (feeling or enjoyment) of the occupant. When the vehicle is in automatic driving, the comfort of the occupant is improved by controlling the vehicle to perform a cradle motion.

  Also, for example, if it is estimated that the occupant is in an uncomfortable state, if the occupant is seated in a seat with a massage function, the massage may be activated or relaxing music or scent may be provided. Good. Further, when it is estimated that the driver is in an uncomfortable state, for example, it may be considered that the risk of an accident is increased, and the driving may be switched to automatic driving (or switching to automatic driving may be promoted). In addition, when automatic driving is being performed, if the uncomfortable state of the occupant (driver) is not improved, it may not be switched to manual driving, and conversely, gravity center braking according to driving by the automatic driving system may be performed. It may be urged to switch to manual operation on the assumption that it is not successful. In addition, if it is estimated that one of the passengers is in an uncomfortable state, the fact may be notified in the vehicle to encourage the vehicle to stop traveling or to take a break temporarily. .

  Note that, in the hardware configuration described in the present specification and illustrated in the drawings, each function is illustrated by a block. However, each function may be hardware and / or a program (for example, a CPU (Central Processing Unit (CPU)). It can be realized by a computer (program that can be executed by a computer such as a processing unit: a central processing unit) or an ECU (Engine Control Unit).

  INDUSTRIAL APPLICABILITY The present invention is applicable to a technique that can estimate the state of a vehicle occupant, in particular, the ride comfort of the vehicle felt by the vehicle occupant.

DESCRIPTION OF SYMBOLS 10 Vehicle behavior sensor 20 Center-of-gravity braking sensor 100, 200, 300, 400 Passenger state estimation apparatus 101, 202 Fluctuation calculation part 102, 203, 303, 402 Comfort degree / discomfort degree estimation part 201, 301 Nonlinear analysis part 302 DFA analysis part 401 Center of gravity braking state determination unit

Claims (12)

An occupant state estimation device for estimating the state of a vehicle occupant,
A vehicle behavior signal including a vehicle behavior indicating the motion of the vehicle and / or the tilt of the vehicle body is acquired from a vehicle behavior sensor that detects the motion of the vehicle and / or the tilt of the vehicle body fixedly installed on the vehicle. A vehicle behavior signal acquisition unit,
A center-of-gravity braking signal acquisition unit that acquires a center-of-gravity braking signal including movement of the center of gravity of the occupant from a center-of-gravity braking sensor that detects the movement of the center of gravity of at least one occupant in the vehicle;
An occupant state estimation unit that estimates whether the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior based on the vehicle behavior signal and the gravity center braking signal;
An occupant state estimation apparatus having an occupant state estimation. The occupant state estimation unit
While calculating the difference between the vehicle behavior signal and the center-of-gravity braking signal, a fluctuation calculating unit that calculates fluctuation of the time series data of the difference,
A comfort / discomfort estimation unit that estimates whether or not the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior, based on fluctuations in the time-series data of the difference,
The occupant state estimation device according to claim 1. The occupant state estimation unit
Calculating a difference between the vehicle behavior signal and the center-of-gravity braking signal, and calculating a Lyapunov exponent related to the time series data of the difference using a method of nonlinear analysis on the time series data of the difference; ,
A fluctuation calculating unit for calculating fluctuations of the time series data of the Lyapunov exponent;
A comfort / discomfort estimation unit that estimates whether or not the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior based on fluctuations in the time series data of the Lyapunov exponent;
The occupant state estimation device according to claim 1. The occupant state estimation unit
Calculating a difference between the vehicle behavior signal and the center-of-gravity braking signal, and calculating a Lyapunov exponent related to the time series data of the difference using a method of nonlinear analysis on the time series data of the difference; ,
A DFA analysis unit for performing DFA analysis on the time series data of the Lyapunov exponent;
A comfort / discomfort estimation unit that estimates whether the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior based on the result of the DFA analysis;
The occupant state estimation device according to claim 1. The occupant state estimation unit
The vehicle behavior signal and the center of gravity braking signal are compared, and the passenger predicts the vehicle behavior and performs the center of gravity braking before the vehicle behavior, or after the vehicle behavior occurs, the vehicle behavior A center-of-gravity braking state determination unit that determines whether center-of-gravity braking is performed following
A comfort / discomfort estimation unit that estimates whether the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior based on the determination result of the gravity center braking state determination unit;
The occupant state estimation device according to claim 1.   The occupant state estimation unit is configured to estimate that the occupant has lost consciousness when an unresponsive state in which the occupant does not perform gravity center braking is detected. The occupant state estimation device according to any one of 5. An occupant state estimation method for estimating the state of a vehicle occupant,
A vehicle behavior signal including a vehicle behavior indicating the motion of the vehicle and / or the tilt of the vehicle body is acquired from a vehicle behavior sensor that detects the motion of the vehicle and / or the tilt of the vehicle body fixedly installed on the vehicle. Vehicle behavior signal acquisition step,
A center-of-gravity braking signal acquisition step of acquiring a center-of-gravity braking signal including a movement of the center of gravity of the occupant from a center-of-gravity braking sensor that detects the movement of the center of gravity of at least one occupant in the vehicle;
An occupant state estimation step for estimating whether the occupant feels good riding comfort of the vehicle with respect to the vehicle behavior based on the vehicle behavior signal and the gravity center braking signal;
An occupant state estimation method. The occupant state estimation step comprises:
A fluctuation calculating step for calculating a difference between the vehicle behavior signal and the gravity center braking signal, and calculating a fluctuation of the time series data of the difference,
A comfort / discomfort estimation step for estimating whether or not the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior based on fluctuations in the time series data of the difference,
The occupant state estimation method according to claim 7. The occupant state estimation step comprises:
A non-linear analysis step of calculating a difference between the vehicle behavior signal and the gravity center braking signal, and calculating a Lyapunov exponent related to the time series data of the difference using a non-linear analysis method with respect to the time series data of the difference; ,
A fluctuation calculating step for calculating fluctuation of the time series data of the Lyapunov exponent;
A comfort / discomfort estimation step for estimating whether or not the occupant feels good ride comfort of the vehicle with respect to the vehicle behavior, based on fluctuations in the time series data of the Lyapunov exponent.
The occupant state estimation method according to claim 7. The occupant state estimation step comprises:
A non-linear analysis step of calculating a difference between the vehicle behavior signal and the gravity center braking signal, and calculating a Lyapunov exponent related to the time series data of the difference using a non-linear analysis method with respect to the time series data of the difference; ,
A DFA analysis step for performing DFA analysis on the time series data of the Lyapunov exponent;
A comfort / discomfort estimation step for estimating whether or not the occupant feels good ride comfort of the vehicle based on the result of the DFA analysis,
The occupant state estimation method according to claim 7. The occupant state estimation step comprises:
The vehicle behavior signal and the center of gravity braking signal are compared, and the passenger predicts the vehicle behavior and performs the center of gravity braking before the vehicle behavior, or after the vehicle behavior occurs, the vehicle behavior A gravity center braking state determination step for determining whether the center of gravity braking is performed following
A comfort / discomfort estimation step for estimating whether or not the occupant feels the comfort of the vehicle with respect to the vehicle behavior based on the determination result in the gravity center braking state determination step;
The occupant state estimation method according to claim 7.   12. The method according to claim 7, wherein when an unresponsive state in which the occupant does not perform gravity center braking is detected, the occupant state estimation step estimates that the occupant has lost consciousness. The passenger state estimation method described in 1.

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