JP2022025732A - Operator's condition estimation apparatus and operator's condition estimation method - Google Patents

Abstract

To provide an operator's condition estimation apparatus and an operator's condition estimation method capable of safely performing measurement without hindering an operation, while reducing introduction costs.SOLUTION: A magnet 11 is provided so as to vibrate with the pulse waves or heartbeat fluctuation of an operator 1 operating a vehicle. A magnetic sensor 12 is provided in the vehicle so as to be able to measure variation in a magnetic field caused by the vibration of the magnet 11. Estimation means is configured to estimate the condition of the operator 1 on the basis of data measured by the magnetic sensor 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a driver's state estimation device and a driver's state estimation method.

Conventionally, as a device for estimating the state of a driver driving a vehicle, information related to the blinking motion of the driver's eyes is detected from a moving image taken by a camera, and the information is used for drowsiness, fatigue, and tension. Data related to heartbeat is acquired by a sensor that estimates a state such as degree (see, for example, Patent Document 1 or 2) or a sensor attached to the fingertip of a driver, and the data is used to estimate a state such as drowsiness. There are some (see, for example, Patent Document 3).

In the heart, regardless of human consciousness, the myocardium of each part of the heart potentially contracts and sends blood to the whole body, and in the electrocardiogram, when the R wave showing the peak and the atrial muscle contract. P-waves and the like generated in the area are observed. The heart rate is the number of times an R wave appears in one minute, and the heart rate variability (beat) is a variation in the interval between R waves (RR interval; RRI; R-R Interval). Since the heartbeat is controlled by the autonomic nervous system, it is possible to extract an index related to the activity of the autonomic nervous system by frequency analysis of the heart rate variability. For example, drowsiness and stress are estimated using a high frequency component HF (High Frequency) of heart rate variability and a low frequency component LF (Low Frequency) (see, for example, Patent Document 3 or 4).

Japanese Unexamined Patent Publication No. 2019-12246 Japanese Unexamined Patent Publication No. 2013-20273 Japanese Unexamined Patent Publication No. 2018-202130 Japanese Unexamined Patent Publication No. 2006-150065

The device for estimating the driver's condition described in Patent Documents 1 and 2 requires a camera for photographing the driver in the vehicle and image analysis software for detecting the blinking motion, and introduction of material costs and the like. There was a problem that the cost was high. In the device for estimating the state of the driver described in Patent Document 3, there is a problem that the sensor attached to the fingertip may interfere with driving, which is extremely dangerous.

The present invention has been made by paying attention to such a problem, and is a driver's state estimation device and a driver's state estimation method which can reduce the introduction cost and can measure safely without getting in the way during driving. The purpose is to provide.

In order to achieve the above object, the driver state estimation device according to the present invention has a magnet provided to vibrate due to a pulse wave or heartbeat fluctuation of the driver who drives the vehicle, and a change in the magnetic field due to the vibration of the magnet. The vehicle is characterized by having a magnetic sensor provided in the vehicle and an estimation means for estimating the state of the driver based on the measurement data of the magnetic sensor.

In the driver state estimation method according to the present invention, a magnet is attached so as to vibrate due to the pulse wave or heartbeat fluctuation of the driver who drives the vehicle, and the change in the magnetic field due to the vibration of the magnet is measured by a magnetic sensor, and the measurement data thereof. It is characterized in that the state of the driver is estimated based on the above.

The driver's state estimation method according to the present invention can be suitably carried out by the driver's state estimation device according to the present invention. The driver's state estimation device and the driver's state estimation method according to the present invention measure the change in the magnetic field due to the vibration of the magnet due to the driver's pulse wave (change in blood flow) or heart rate variability by measuring with a magnetic sensor. For example, the driver has drowsiness or stress by using the RR interval of the heart rate variability obtained from the measured pulse wave, or the high frequency component HF or the low frequency component LF of the RR interval of the directly measured heart rate variability. It is possible to estimate the driver's condition, such as whether or not it is. Since the driver's state estimation device and the driver's state estimation method according to the present invention can measure the driver's pulse wave or heart rate variability by a relatively simple configuration of a magnet and a magnetic sensor, a moving image is captured. There is no need for a camera or expensive image analysis software, and the introduction cost such as material cost can be reduced. In addition, the magnet and magnetic sensor can be attached in a place that does not interfere with driving, and measurement can be performed safely.

In the driver's state estimation device and the driver's state estimation method according to the present invention, the magnet may be a permanent magnet or an electromagnet, and in the case of an electromagnet, it may be a DC electromagnet or an AC electromagnet. There may be. Further, the magnetic sensor may be any as long as it has a sensitivity capable of measuring the vibration of the magnet due to the driver's pulse wave or heartbeat fluctuation, and for example, an AMR sensor, a GMR sensor, a TMR sensor, or an MI sensor. Any magnetometer, such as a fluxgate sensor, may be used as long as the magnetic field can be measured, but it is preferably composed of a small TMR sensor so that it can be easily attached to a vehicle.

In the driver's state estimation device and the driver's state estimation method according to the present invention, the magnet is provided so as to have a vibration component parallel to the road surface on which the vehicle travels, and the magnetic sensor is a magnet of the magnet. It is preferable that the vibration component is provided so as to be measurable. In this case, the influence of the vertical vibration of the moving vehicle can be reduced, and the vibration of the magnet can be measured with high accuracy.

In the driver's state estimation device and the driver's state estimation method according to the present invention, it is preferable that the magnet is provided in a state where pressure is applied to the driver who drives the vehicle. In this case, the magnet can easily capture the driver's pulse wave and heart rate variability, and the driver's pulse wave and heart rate variability can be measured with high accuracy.

In the driver's state estimation device and the driver's state estimation method according to the present invention, the magnet may be provided anywhere as long as it is provided to vibrate due to the pulse wave or heart rate variability of the driver who drives the vehicle. Often, for example, the driver's body surface can be fixed near the heart, groove, back, chest, temples, carotid artery, wrist, ankle, buttocks, thigh, digestive organs, or face. It may have been. Further, the magnet may be provided on the seat belt, seat surface, backrest, headrest, or steering wheel of the vehicle in the driver's seat of the vehicle. For example, in order to provide a magnet while applying pressure to a driver who drives a vehicle, the magnet may be provided on the seat belt, seat surface, and backrest of the driver's seat of the vehicle.

In the driver's state estimation device according to the present invention, the magnets are composed of a plurality of magnets, each of which is arranged at intervals along the extension direction of the blood vessel of the driver who drives the vehicle, and the magnetic sensor is , The change in the magnetic field due to the vibration of each magnet can be measured, and the estimation means obtains the pulse wave propagation velocity of the driver based on the measurement data of the magnetic sensor, and based on the pulse wave propagation velocity, The state of the driver may be estimated. In this case, for example, the blood pressure of the driver can be obtained from the pulse wave velocity, and the state of the driver can be estimated based on the blood pressure. Further, for example, the state of the driver can be estimated in more detail by using the obtained blood pressure and the high frequency component HF or the low frequency component LF of the RR interval of the heart rate variability.

The driver state estimation device according to the present invention is a reference magnet provided in the vehicle at a position away from the driver who drives the vehicle, and a reference provided so as to be able to measure the magnetic field of the reference magnet. The estimation means may be configured to use the measurement data of the reference magnetic sensor to reduce noise included in the measurement data of the magnetic sensor. In this case, since the vibration of the moving vehicle can be measured by the reference magnet and the reference magnetic sensor, the noise included in the measurement data of the magnetic sensor is removed by subtracting the vibration from the measurement data of the magnetic sensor. Can be mitigated. It is preferable that the reference magnet is provided at a position where it does not vibrate due to the pulse wave or heart rate variability of the driver who drives the vehicle, and the reference magnetic sensor is provided at a position where only the vibration of the reference magnet can be measured. ..

Further, in the driver's state estimation device according to the present invention, the magnets may be composed of a plurality of magnets and may be arranged in a predetermined range in the same direction. The smaller the range occupied by the magnet, the narrower the peak width of the measured fluctuation, and the RR interval of the heart rate variability can be detected accurately, but the output becomes smaller. Further, if the range occupied by the magnet is large, the output is large, but the detection range is wide, so that the peak width of the measured fluctuation becomes wide. Therefore, by considering the magnitude of the output and the accuracy of the measured fluctuation on the time axis, and performing the measurement by arranging multiple magnets in the optimum range, the driver's condition can be determined under the optimum conditions. Can be estimated.

According to the present invention, it is possible to reduce the introduction cost, and to provide a driver's state estimation device and a driver's state estimation method that can be safely measured without getting in the way during driving.

It is a side view which shows the use state of the state estimation apparatus of the driver of embodiment of this invention. It is (a) plan view and (b) side view which shows the modification of the driver state estimation apparatus of embodiment of this invention in which a plurality of magnets and a plurality of magnetic sensors are regularly arranged and installed in an array. It is a front view which shows the attachment state of the magnet, the magnetic sensor, the pulse transducer, and the electrocardiogram to the subject of the pulse wave measurement experiment which concerns on the state estimation apparatus of the driver of embodiment of this invention. 3 is a graph showing the measurement results of (a) a magnetic sensor (TMR), (b) a pulse transducer, and (c) an electrocardiogram (ECG) in the pulse wave measurement experiment shown in FIG. In the pulse wave measurement experiment shown in FIG. 3, (a) the relationship between the RR interval (RR Interval of TMR) obtained from the measurement result of the magnetic sensor and the RR interval (RR Interval of ECG) obtained from the measurement result of the electrocardiogram. The graph shown is a partially enlarged graph of (b) and (a). The RR interval obtained from the measurement result of the magnetic sensor and the RR interval (RR Interval of Pulse) obtained from the measurement result of the pulse transducer in the pulse wave measurement experiment shown in FIG. 3, and the RR interval obtained from the measurement result of the electrocardiogram. It is a graph which shows the relationship. The relationship between the RR interval obtained from the measurement result of the magnetic sensor and the RR interval obtained from the measurement result of the electrocardiogram when the subject performed the measurement while sitting on the chair in the pulse wave measurement experiment shown in FIG. It is a graph which shows. A side view showing a state in which a magnet and a magnetic sensor are attached to a subject in a pulse wave measurement experiment relating to a state estimation device for a driver according to an embodiment of the present invention, and (b) a graph showing the measurement results of the magnetic sensor. be. In the pulse wave measurement experiment for the driver's state estimator according to the embodiment of the present invention, (a) the range occupied by the plurality of magnets in the four cases where the experiment is performed, and the range occupied by the smallest 5 cm × 5 cm. It is a plan view which shows the arrangement of magnets, (b) is the plan view which shows the arrangement of magnets in 17cm × 17cm which the area occupied by a plurality of magnets is the largest. It is a graph which shows the relationship between the area occupied by each magnet, and the mean absolute error in four cases where the range occupied by a plurality of magnets is different in the pulse wave measurement experiment shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 10 show a driver's state estimation device and a driver's state estimation method according to the embodiment of the present invention.
As shown in FIG. 1, the driver state estimation device according to the embodiment of the present invention includes a magnet 11, a magnetic sensor 12, and an estimation means (not shown).

The magnet 11 is made of a permanent magnet and is provided so as to vibrate by the pulse wave or heart rate variability of the driver 1 who drives the vehicle. In a specific example shown in FIG. 1, the magnet 11 is provided on the seat surface of the driver's seat 2 of the vehicle, and when the driver 1 who drives the vehicle sits on the driver's seat 2, the magnet 11 is provided with respect to the driver 1. It is provided so that it is in a state where pressure is applied.

The magnet 11 is not limited to a permanent magnet, and may be an electromagnet. In that case, the magnet 11 may be a DC electromagnet or an AC electromagnet. Further, the magnet 11 is not limited to the seat surface of the driver's seat 2, and may be provided anywhere as long as it is provided to vibrate due to the pulse wave or heart rate fluctuation of the driver 1 who drives the vehicle. For example, the driver. Of the body surface of 1, it may be provided so as to be fixed to the vicinity of the heart, the groove, the back, the chest, the temple, the vicinity of the carotid artery, the wrist, the ankle, the buttocks, the thigh, the vicinity of the digestive organs, or the face. It may be provided on the seat belt, backrest, or headrest of the driver's seat 2 of the vehicle, or on the handle of the vehicle. The magnet 11 is preferably provided on the seat belt, backrest, or the like of the driver's seat 2 of the vehicle in order to put pressure on the driver 1 who drives the vehicle. Further, the number of magnets 11 may be one or a plurality.

The magnetic sensor 12 is provided in the vehicle so that the change in the magnetic field due to the vibration of the magnet 11 can be measured. In a specific example shown in FIG. 1, the magnetic sensor 12 is provided below the driver's seat 2 of the vehicle so that the change in the magnetic field due to the vibration of the magnet 11 provided on the seat surface of the driver's seat 2 of the vehicle can be measured. ing. Further, the magnetic sensor 12 is made of a small TMR sensor that can be easily attached to a vehicle. The magnetic sensor 12 is not limited to the TMR sensor, and may be any sensor as long as it has a sensitivity capable of measuring the vibration of the magnet 11 due to the pulse wave of the driver 1 or the heartbeat fluctuation. For example, the AMR sensor. , GMR sensor, MI sensor, fluxgate sensor and the like.

The estimation means comprises a computer, is connected to the magnetic sensor 12, and is configured to receive the measurement data of the magnetic sensor 12. Further, the estimation means is configured to estimate the state of the driver 1 based on the received measurement data of the magnetic sensor 12. In a specific example shown in FIG. 1, the estimation means is built in a driver monitoring system (DMS) mounted on a vehicle. Further, when the pulse wave is measured by the magnet 11 and the magnetic sensor 12, the estimation means obtains the RR interval of the heart rate variability from the pulse wave included in the measurement data. The estimation means estimates whether or not the driver 1 has drowsiness or stress by using the heart rate variability obtained from the pulse wave, or the high frequency component HF or the low frequency component LF of the measured heart rate variability RR interval. It is designed to do. Further, the estimation means may be configured to estimate the state of the driver 1 by using the heart rate obtained from the measurement data. The DMS warns the driver 1 by sound or light when the driver 1 is presumed to be drowsy by the estimation means.

The vehicle is not limited to a general vehicle, and may be any vehicle such as a business vehicle or an autonomous driving vehicle. Further, the driver 1 is not limited to a healthy person, and may be any driver 1 such as a physically handicapped person or an elderly person.

Next, the operation will be described.
The driver state estimation method according to the embodiment of the present invention can be suitably carried out by the driver state estimation device according to the embodiment of the present invention. The driver state estimation device and the driver state estimation method according to the embodiment of the present invention measure the change in the magnetic field due to the vibration of the magnet 11 due to the pulse wave or heart rate variability of the driver 1 by the magnetic sensor 12. , The state of the driver 1 can be estimated, such as whether the driver 1 has drowsiness or stress. In the driver state estimation device and the driver state estimation method according to the embodiment of the present invention, the pulse wave or heart rate variability of the driver 1 can be measured by a relatively simple configuration of the magnet 11 and the magnetic sensor 12. Therefore, a camera for shooting moving images and expensive image analysis software are not required, and introduction costs such as material costs can be reduced. Further, the magnet 11 and the magnetic sensor 12 can be attached to a place that does not interfere with the operation, and the measurement can be performed safely.

In the driver state estimation device and the driver state estimation method according to the embodiment of the present invention, as shown in FIG. 1, a magnet 11 is provided so as to put pressure on the driver 1 who drives the vehicle. Thereby, the pulse wave and the heart rate variability of the driver 1 can be easily captured by the magnet 11, and the pulse wave and the heart rate variability of the driver 1 can be measured accurately.

In the driver's state estimation device and the driver's state estimation method according to the embodiment of the present invention, the smaller the installation area of the magnet 11 or the range occupied by each magnet 11 when a plurality of magnets 11 are used, the smaller the measurement. The peak width of the fluctuation is narrowed, and the RR interval and the like can be detected accurately, but the output becomes small. Further, if the installation area of the magnet 11 or the range occupied by the plurality of magnets 11 is large, the output becomes large, but the detection range becomes wide, so that the peak width of the measured fluctuation becomes wide. Therefore, in consideration of the magnitude of the output and the accuracy of the measured fluctuation on the time axis, it is possible to use the magnet 11 having the optimum size or to arrange a plurality of magnets 11 in the optimum range. preferable.

Further, in the driver state estimation device and the driver state estimation method according to the embodiment of the present invention, a magnet 11 is provided so as to have a vibration component parallel to the road surface on which the vehicle travels, and the vibration component of the magnet 11 is provided. It is preferable to provide the magnetic sensor 12 so that the above can be measured. In this case, the influence of the vertical vibration of the moving vehicle can be reduced, and the vibration of the magnet 11 can be measured with high accuracy.

Further, in the driver state estimation device according to the embodiment of the present invention, the magnets 11 are composed of a plurality of magnets 11 and are arranged at intervals along the extension direction of the blood vessel of the driver 1 who drives the vehicle. The magnetic sensor 12 can measure the change in the magnetic field due to the vibration of each magnet 11, and the estimation means obtains the pulse wave propagation velocity of the driver 1 based on the measurement data of the magnetic sensor 12, and the pulse wave propagation velocity thereof. The state of the driver 1 may be estimated based on the above. In this case, for example, the blood pressure of the driver 1 can be obtained from the pulse wave velocity, and the state of the driver 1 can be estimated based on the blood pressure. Further, for example, the state of the driver 1 can be estimated in more detail by using the obtained blood pressure and the high frequency component HF or the low frequency component LF of the RR interval of the heart rate variability.

Further, as shown in FIG. 2, in the driver state estimation device according to the embodiment of the present invention, a plurality of magnets 11 are regularly arranged and installed in an array, and a plurality of magnetic sensors 12 are also regularly arranged and installed in an array. You may be. In this case, noise can be efficiently removed from the measurement data, the S / N ratio can be increased, and the pulse wave or heart rate variability of the driver 1 can be measured accurately. Further, in this case, each magnet 11 may be composed of an electromagnet having a different natural frequency, and each magnetic sensor 12 may also have a corresponding measurement frequency. Alternatively, each magnet 11 is composed of an electromagnet having a different natural frequency, and a magnetic sensor 12 having a smaller number than the number of the magnets 11 transfers a signal from each magnet 11 having a different natural frequency by time division multiplexing (TDM) or the like. It may be configured to receive using. With these, it is possible to perform more detailed analysis such as further improving the measurement accuracy and obtaining the distance to the vibration source.

Further, the driver state estimation device according to the embodiment of the present invention can measure the magnetic field of the reference magnet 11 and the reference magnet 11 provided in the vehicle at a position away from the driver 1 who drives the vehicle. It has a reference magnetic sensor 12 provided, and the estimation means may be configured to reduce noise included in the measurement data of the magnetic sensor 12 by using the measurement data of the reference magnetic sensor 12. .. In this case, the reference magnet 11 and the reference magnetic sensor 12 can measure the vibration of the moving vehicle. Therefore, by subtracting the vibration from the measurement data of the magnetic sensor 12, the measurement data of the magnetic sensor 12 can be obtained. The included noise can be reduced. The reference magnet 11 is provided at a position where it does not vibrate due to the pulse wave or heart rate variability of the driver 1 who drives the vehicle, and the reference magnetic sensor 12 is provided at a position where only the vibration of the reference magnet 11 can be measured. It is preferable to have.

A pulse wave measurement experiment was conducted to investigate that the pulse wave can be measured by the vibration of the magnet 11. In the experiment, as shown in FIG. 3, a magnet 11 having a diameter of 3 mm was taped to a position close to the heart on the left side of the subject's dovetail, and the fluctuation of the magnet 11 due to the pulse wave was measured by a magnetic sensor consisting of a TMR sensor. Measured at 12. The distance between the magnet 11 and the magnetic sensor 12 was set to about 300 mm. For comparison, ECG electrode pads were attached near both shoulders and the left flank of the subject, and electrocardiogram (ECG) was measured. In addition, a pulse transducer using a piezo element was attached to the fingertip of the ring finger of the subject's left hand, and the pulse wave was measured.

The measurement results of the magnetic sensor 12, the pulse transducer, and the electrocardiogram are shown in FIG. Further, the peak position of the measured waveform of the magnetic sensor 12 is obtained, and is indicated by a circle in FIG. 4A. As shown in FIG. 4, the measured waveform of the magnetic sensor 12 is noisy and appears to be slightly disturbed as compared with the waveforms of the pulse transducer and the electrocardiogram, but it is confirmed that the waveform repeats regularly. rice field. It was also confirmed that the peak position of the waveform moves in the order of the electrocardiogram, the magnetic sensor 12, and the pulse transducer according to the distance from the heart. From this, it can be said that the pulse wave is measured by the magnetic sensor 12 and the RR interval of the heart rate variability can be extracted.

From each measurement result shown in FIG. 4, each RR interval was obtained. FIG. 5 shows the relationship between the RR interval (RR Interval of TMR) obtained from the measurement result of the magnetic sensor 12 and the RR interval (RR Interval of ECG) obtained from the measurement result of the electrocardiogram. As shown in FIG. 5, it was confirmed that the two RR intervals are highly correlated. The mean absolute error (MAE) when measured about 100 times was 4.0 ms.

FIG. 6 shows the graph of FIG. 5A in which the relationship between the RR interval (RR Interval of Pulse) obtained from the measurement result of the pulse transducer and the RR interval obtained from the measurement result of the electrocardiogram is superimposed. As shown in FIG. 6, the correlation between the pulse transducer and the electrocardiogram is also high, but it was confirmed that the relationship between the magnetic sensor 12 and the electrocardiogram is slightly higher.

4 to 6 show the measurement results when the subject is lying on the bed, and the RR interval obtained from the measurement results of the magnetic sensor 12 when the subject is sitting on the chair. FIG. 7 shows the relationship between the RR interval and the RR interval obtained from the measurement results of the electrocardiogram. As shown in FIG. 7, it was confirmed that the relationship between the two RR intervals was slightly lower than that in FIG. 5, but had a high correlation. The mean absolute error (MAE) when measured about 100 times was 11.9 ms.

As shown in FIG. 8A, a magnet 11 having a diameter of 3 mm was attached with tape near the carotid artery on the left side of the subject's neck, and the fluctuation of the magnet 11 due to the pulse wave was placed behind the subject's neck. The measurement was performed by a magnetic sensor 12 composed of sensors. The distance between the magnet 11 and the magnetic sensor 12 was set to 250 mm to 300 mm. The measurement result of the magnetic sensor 12 is shown in FIG. 8 (b). As shown in FIG. 8 (b), it was confirmed that the waveform was regularly repeated and the peak position was clear. From this, it can be said that the pulse wave is measured and the RR interval of the heart rate variability can be extracted.

An experiment was conducted to investigate the change in the accuracy of pulse wave measurement depending on the size of the magnet 11 (the range occupied by the magnet 11). In the experiment, as shown in FIG. 9, 16 magnets 11 having a diameter of 3 mm were arranged in a square with 4 vertical × 4 horizontal at equal intervals on the seat on which the subject sits. The magnets 11 were all oriented in the same direction and arranged so that the same poles faced the subject. In the experiment, the pulse wave was measured in four cases where one side of the square occupied by the 16 magnets 11 was 5 cm, 10 cm, 15 cm, and 17 cm by changing the interval of each magnet 11. Further, in the experiment, the fluctuation of each magnet 11 due to the pulse wave was measured by the magnetic sensor 12 composed of the TMR sensor while the subject was sitting on the seat. The distance between the nearest magnet 11 and the magnetic sensor 12 was set to about 300 mm.

In the experiment, ECG electrode pads were attached to the vicinity of both shoulders and the vicinity of the left flank of the subject, and the electrocardiogram (ECG) was measured at the same time as the measurement using each magnet 11. In the four cases where the range occupied by each magnet 11 is different, the RR interval of the heart rate variability is obtained from the magnetic sensor 12 and the electrocardiogram measurement data, respectively, and the RR interval is obtained from the electrocardiogram measurement data in the same manner as in the first embodiment. The average absolute error (MAE) of the RR interval obtained from the measurement data of the magnetic sensor 12 was obtained.

The relationship between the area occupied by each magnet 11 and the mean absolute error is shown in FIG. In FIG. 10, an approximate curve based on a linear equation for each data is shown by a broken line. As shown in FIG. 10, a positive correlation was observed between the area occupied by each magnet 11 and the mean absolute error, and it was confirmed that the mean absolute error was also reduced by reducing the area occupied by each magnet 11. Was done. In order to secure an output of a certain magnitude as the output of the magnet 11, there is a limit to reducing the area occupied by each magnet 11, but from FIG. 10, for example, the mean absolute error is suppressed to within 10 msec. Therefore, it can be said that the area occupied by each magnet 11 should be 12 cm × 12 cm (position of × mark in FIG. 10) or less.

In this experiment, permanent magnets are used as each magnet 11, but by using an electromagnet, each magnet 11 can be widely distributed in advance and only the magnet 11 in a necessary range can be driven. As a result, the balance between the output of each magnet 11 and the error can be adjusted according to the measurement conditions and the situation at the time of measurement, and the state of the driver can be estimated by performing the measurement under the optimum conditions.

1 Driver 2 Driver's seat

11 magnet 12 magnetic sensor

Claims (11)

A magnet provided to vibrate due to the pulse wave or heart rate variability of the driver driving the vehicle,
With the magnetic sensor provided in the vehicle, it is possible to measure the change in the magnetic field due to the vibration of the magnet.
An estimation means for estimating the state of the driver based on the measurement data of the magnetic sensor.
A driver's state estimation device, characterized by having. The magnet is provided so as to have a vibration component parallel to the road surface on which the vehicle travels.
The driver's state estimation device according to claim 1, wherein the magnetic sensor is provided so as to be capable of measuring the vibration component of the magnet. The driver's state estimation device according to claim 1 or 2, wherein the magnet is provided in a state where pressure is applied to the driver who drives the vehicle. The magnet can be fixed to the driver's body surface near the heart, epigastrium, back, chest, temples, near the carotid artery, wrist, ankle, buttocks, thigh, near the digestive organs, or on the face. The driver's state estimation device according to any one of claims 1 to 3, wherein the device is characterized by the above. The invention according to any one of claims 1 to 3, wherein the magnet is provided on a seat belt, a seat surface, a backrest, a headrest, or a steering wheel of the vehicle. Driver's state estimator. One of claims 1 to 5, wherein the estimation means is configured to estimate whether the driver is drowsy or stressed as the state of the driver. The driver state estimation device described in the section. The magnets are composed of a plurality of magnets, and are arranged at intervals along the extension direction of the blood vessels of the driver who drives the vehicle.
The magnetic sensor can measure changes in the magnetic field due to the vibration of each magnet.
The estimation means is characterized in that the pulse wave velocity of the driver is obtained based on the measurement data of the magnetic sensor, and the state of the driver is estimated based on the pulse wave velocity. The driver's state estimation device according to any one of 1 to 6. A reference magnet provided on the vehicle at a position away from the driver who drives the vehicle, and a reference magnet.
It has a reference magnetic sensor provided so as to be able to measure the magnetic field of the reference magnet.
One of claims 1 to 7, wherein the estimation means is configured to reduce noise included in the measurement data of the magnetic sensor by using the measurement data of the reference magnetic sensor. The driver state estimation device described in the section. The driver's state estimation device according to any one of claims 1 to 7, wherein the magnet is composed of a plurality of magnets and is arranged in a predetermined range in the same direction. The driver's state estimation device according to claim 9, wherein the predetermined range is a range of 12 cm × 12 cm or less. A magnet is attached so as to vibrate due to the pulse wave or heart rate variability of the driver who drives the vehicle, the change in the magnetic field due to the vibration of the magnet is measured by a magnetic sensor, and the state of the driver is estimated based on the measurement data. A driver's condition estimation method, characterized in that.

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