CN114771379B - Seat headrest, vehicle and fatigue level detection method - Google Patents

Abstract

The invention discloses a seat headrest, a vehicle and a fatigue level detection method, wherein in the seat headrest, one side of a headrest framework, which is far away from a seat back, is fixedly connected with one end, which is far away from the seat back, of a slide bar to form a first connecting part, and the other end of the slide bar is connected with the seat back; one side of the outer headrest panel is fixedly connected to the first connecting part in a lap joint manner, and the other side of the outer headrest panel naturally sags; at least one biosensor is arranged on one side surface of the headrest outer panel away from the headrest framework, contacts the head of the driver, is used for collecting biological signals of the driver, and outputs first electric signals corresponding to the biological signals; the processing chip is configured on the headrest framework and is used for receiving and processing the first electric signal and generating a second electric signal corresponding to the fatigue level based on the preset fatigue level model and the first electric signal; the feedback component is electrically connected with the processing chip and is used for making corresponding feedback actions according to the second electric signal so as to accurately monitor the fatigue level of the driver.

Description

Seat headrest, vehicle and fatigue level detection method

Technical Field

The present invention relates to the technical field of vehicles, and in particular to a seat headrest, a vehicle and a fatigue level detection method.

Background Art

With the development of intelligent driving technology, users have higher and higher requirements for the safety of intelligent driving, especially when driving long distances or traveling outdoors. They require the car to automatically identify whether the user's driving status is normal, and to identify quickly and accurately without affecting comfort. The stronger the driving status recognition ability of the car, the less likely it is to cause a collision accident, and the safer it is for the user.

At present, fatigue driving detection generally adopts the behavior analysis of the driver or the image analysis of the driver's face and eye features. However, due to the different static or dynamic habits of each person, for a driver who likes static driving, he may always keep a single action or expression, and eventually be misjudged as fatigued when he is not yet fatigued; for a driver who likes dynamic driving, he may have rich actions or rich expressions, and when he is fatigued, he may be misjudged as not fatigued. Therefore, these two methods cannot accurately monitor the fatigue status of the driver.

Summary of the invention

The invention provides a seat headrest, a vehicle and a fatigue level detection method, so as to realize accurate monitoring of the fatigue level of a driver.

To achieve the above-mentioned purpose, the first embodiment of the present invention provides a seat headrest, comprising: a filling sponge, a headrest skin and a slide bar; and further comprising:

A headrest frame, wherein one side of the headrest frame away from the seat back is fixedly connected to one end of the slide rod away from the seat back to form a first connection portion, and the other end of the slide rod is connected to the seat back;

A headrest outer panel, one side of which is overlapped and fixed on the first connecting portion, and the other side of which is naturally drooped;

At least one biosensor, at least one of the biosensors is arranged on a side surface of the headrest outer panel away from the headrest frame, contacts the driver's head, is used to collect a biosignal of the driver, and outputs a first electrical signal corresponding to the biosignal;

a processing chip, the processing chip being configured on the headrest frame, for receiving and processing the first electrical signal, and generating a second electrical signal corresponding to the fatigue level based on a preset fatigue level model and the first electrical signal;

A feedback component is electrically connected to the processing chip, and is used to perform a corresponding feedback action according to the second electrical signal.

According to an embodiment of the present invention, the headrest frame is located between the headrest outer panel and the plane formed by the slide bar itself.

According to one embodiment of the present invention, the seat headrest further comprises:

A headrest inner panel, one side of which is overlapped and fixed on the first connecting portion to form a second connecting portion, and the headrest inner panel is used to wrap the headrest frame and the processing chip; one side of the headrest outer panel is overlapped and fixed on the second connecting portion.

According to an embodiment of the present invention, the feedback component includes: a vibration component, located between the headrest inner panel and the headrest outer panel, and configured to drive the headrest outer panel to vibrate according to the second electrical signal.

According to an embodiment of the present invention, the feedback component includes: a buzzer or an electric horn, located at one end of the headrest frame adjacent to the seat back, for issuing a warning sound according to the second electrical signal.

According to one embodiment of the present invention, a speaker cover is provided at one end of the headrest outer panel adjacent to the seat back and abutting against the buzzer or electric horn, and the speaker cover is used to accommodate the buzzer or electric horn and also for sound amplification.

According to one embodiment of the present invention, the biosensor is a brain wave sensor.

To achieve the above object, the second embodiment of the present invention further provides a vehicle, comprising: the seat headrest as described above; the seat headrest is mounted on the seat back; the slide bar is telescopically connected to the seat back;

Also includes: vehicle controller and display screen;

The vehicle controller communicates with the processing chip, and the vehicle controller is used to control the display screen to display corresponding warning information according to the second electrical signal generated by the processing chip processing the first electrical signal.

According to one embodiment of the present invention, the processing chip is also used to receive and process a third electrical signal, and send a signal to start the assisted driving system to the vehicle controller based on the processed third electrical signal and the abnormal sample model, and the vehicle controller controls the assisted driving system to start according to the signal to start the assisted driving system.

To achieve the above object, the third aspect of the present invention further proposes a fatigue level detection method, which is implemented based on the vehicle as described above and includes the following steps:

receiving a biological signal of the driver collected by the biosensor, and generating a first electrical signal according to the biological signal;

processing the first electrical signal;

generating a second electrical signal according to the processed first electrical signal and a preset fatigue level model;

According to the second electrical signal, the feedback component is controlled to generate a corresponding feedback action; wherein the steps of establishing the preset fatigue level model are as follows:

Multiple fatigue levels are divided according to the driver's brain wave frequency range and the driver's corresponding physical condition;

A brain wave signal power spectrum density characteristic matrix is established for each fatigue level.

According to an embodiment of the present invention, processing the first electrical signal includes:

noise reduction processing of the first electrical signal;

The generating the second electrical signal according to the first electrical signal and a preset fatigue level model comprises:

Calculating the power spectrum density of the first electrical signal after the noise reduction processing to obtain a characteristic matrix of the first electrical signal;

Obtaining the similarity weights of the power spectrum density feature matrix of the brain wave signal corresponding to each fatigue level in the preset fatigue level model and the feature matrix of the first electrical signal;

A second electrical signal having a fatigue level corresponding to the first electrical signal is output according to the similarity weight.

According to the seat headrest, vehicle and fatigue level detection method proposed in the embodiment of the present invention, the seat headrest includes: filling sponge, headrest skin, slide rod, headrest frame, headrest outer panel, at least one biosensor, processing chip and feedback component, the side of the headrest frame away from the seat back is fixedly connected with the end of the slide rod away from the seat back to form a first connection part, and the other end of the slide rod is connected to the seat back; one side of the headrest outer panel is overlapped and fixed on the first connection part, and the other side of the headrest outer panel naturally droops; at least one biosensor is arranged on the side surface of the headrest outer panel away from the headrest frame, contacts the driver's head, is used to collect the driver's biological signal, and outputs a first electrical signal corresponding to the biological signal; the processing chip is configured on the headrest frame, is used to receive and process the first electrical signal, and generates a second electrical signal corresponding to the fatigue level based on the preset fatigue level model and the first electrical signal; the feedback component is electrically connected to the processing chip, and the feedback component is used to make a corresponding feedback action according to the second electrical signal. In order to accurately monitor the driver's fatigue level.

It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG1 is a schematic structural diagram of a seat headrest provided in an embodiment of the present invention;

Fig. 2 is a right side view of Fig. 1;

3 is a schematic structural diagram of an outer panel of a headrest in a seat headrest provided in an embodiment of the present invention;

4 is a schematic diagram of the structure of a headrest outer panel film in a seat headrest provided in an embodiment of the present invention;

5 is a block diagram showing the connection of a processing chip, a biosensor, and a feedback component in a seat headrest according to an embodiment of the present invention;

FIG6 is a block diagram of a vehicle according to an embodiment of the present invention;

7 is a flow chart of a fatigue level detection method proposed in an embodiment of the present invention;

8 is a diagram showing the steps of processing a first electrical signal in a fatigue level detection method according to an embodiment of the present invention;

9 is a flow chart of establishing a fatigue level model in the fatigue level detection method proposed in an embodiment of the present invention;

10 is a diagram showing the relationship between fatigue and driving time in the fatigue level detection method proposed in an embodiment of the present invention;

11 is a similarity curve between a sampled brain wave A with a consistency index of 0.3 and a fatigue level 4 in the fatigue level detection method proposed in an embodiment of the present invention;

FIG. 12 is a similarity curve between a sampled brain wave B with a consistency index of 0.6 and fatigue level 4 in the fatigue level detection method proposed in an embodiment of the present invention.

DETAILED DESCRIPTION

In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

FIG1 is a schematic diagram of the structure of a seat headrest according to an embodiment of the present invention. As shown in FIGS. 1 to 4 , the seat headrest 100 comprises: a filling sponge 101, a headrest skin 102, a slide bar 103, a headrest frame 104, a headrest outer panel 105, at least one biosensor 106, a processing chip 107 and a feedback component 108.

Among them, one side of the headrest frame 104 away from the seat back is fixedly connected to one end of the slide rod 103 away from the seat back to form a first connection part, and the other end of the slide rod 103 is connected to the seat back; one side of the headrest outer panel 105 is overlapped and fixed on the first connection part, and the other side of the headrest outer panel 105 naturally droops; at least one biosensor 106 is arranged on the side surface of the headrest outer panel 105 away from the headrest frame 104, contacting the driver's head, for collecting the driver's biological signal, and outputting a first electrical signal corresponding to the biological signal; the processing chip 107 is configured on the headrest frame 104, for receiving and processing the first electrical signal, and generating a second electrical signal corresponding to the fatigue level based on a preset fatigue level model and the first electrical signal; the feedback component 108 is electrically connected to the processing chip 107, and the feedback component 108 is used to make a corresponding feedback action according to the second electrical signal.

It should be noted that the slide bar 103 includes a U-shaped slide bar portion with a gradually widening opening, and a portion that contacts the seat back in parallel with each other (as shown in FIG. 1 ). The connection between the two portions has a certain angle (as shown in FIG. 2 ) to adapt to the driver's head support from a biological perspective, allowing the driver to drive more comfortably.

The headrest frame 104 can be a U-shaped frame (as shown in FIG. 1 ), and the open end of the U-shaped frame is fixedly connected to the U-shaped bottom of the U-shaped slide rod portion whose opening gradually widens. Optionally, the headrest frame 104 can be welded to the U-shaped bottom of the U-shaped slide rod portion whose opening gradually widens. The connected headrest frame 104 and the bottom of the U-shaped slide rod portion whose opening gradually widens surround a plane. The headrest frame 104 supports the headrest structure and meets the relevant strength requirements of regulations and the relevant requirements of whiplash tests.

The processing chip 107 can be installed on the headrest frame 104. Optionally, the processing chip 107 can be installed in a shell, and a buckle can be provided on the shell to buckle on the headrest frame 104. Alternatively, screw holes are provided on the headrest frame 104, and screw holes are also provided on the shell, and the headrest frame 104 and the shell are fixedly connected by bolts. Alternatively, the headrest frame 104 can be bonded to the shell. It can also be other fixed installation methods well known to those skilled in the art, and the present invention does not specifically limit this.

The outer panel 105 of the headrest can be set to a shape as shown in Figure 3, and the part connected to the first connecting part of the outer panel 105 of the headrest can be overlapped on the first connecting part with an arc. The outer panel 105 of the headrest can be made of flexible materials, such as TPE resin with adjustable hardness, molded sponge, etc. The thickness of the panel is between 3mm and 5mm. The whole panel must have a certain hardness to maintain the overall shape of the product and to assemble and fix the biosensor 106 and the speaker cover 110, and have a certain deformation resilience performance to facilitate the adjustment of the comfort of the headrest. The part of the outer panel 105 of the headrest overlapped on the first connecting part can be directly bonded to the first connecting part. Alternatively, one side of the outer panel 105 of the headrest can be set to a hat shape and directly put on the first connecting part.

The biosensor 106 may be one or more. When there is one, it may be installed at the center of the headrest outer panel 105. When there are more than one, they may be evenly installed on the surface of the headrest outer panel 105 (as shown in FIG. 3 ). After the biosensor 106 is installed, a transparent film 111 may be covered on one side of the headrest outer panel 105 where the biosensor 106 is installed (as shown in FIG. 4 ) to protect the biosensor 106.

The filling sponge 101 can fill the headrest, and finally the headrest is wrapped with the headrest skin 102 to form a seat headrest 100 (as shown in FIGS. 1 and 2 ).

It can be understood that the working principle of the seat headrest 100 is as follows: as shown in Figure 5, the biosensor 106 and the feedback component 108 are electrically connected to the processing chip 107 respectively. The biosensor 106 collects the driver's biological signals (brain waves, electromyography, heart rate, etc.) during driving, and converts the biological signals into a first electrical signal, and transmits it to the processing chip 107. The processing chip 107 processes the first electrical signal, and based on a preset fatigue level model, outputs a second electrical signal of a fatigue level corresponding to the first electrical signal, and controls the feedback component 108 to make corresponding feedback actions according to the second electrical signal (wherein, the power supply lines of the biosensor 106, the feedback component 108 and the processing chip 107 can pass through the inside of the sliding rod 103 and be connected to the power supply circuit of the entire vehicle).

For example, the preset fatigue level module can be divided into nine levels from 0 to 9, and the larger the value, the higher the degree of fatigue. For example, 0 is a non-fatigue level, 4 is a mild fatigue level, 7 is a moderate fatigue level, and 9 is an extreme fatigue level. After the biosensor 106 collects the driver's biological signal and converts it into a first electrical signal, the processing chip 107 processes the first electrical signal and compares it with the preset fatigue level model. The result output is that the fatigue level corresponding to the first electrical signal is 4, then the second electrical signal corresponding to 4 is output, and the feedback component 108 is controlled to perform a mild feedback action according to the second electrical signal; when the result outputs that the fatigue level corresponding to the first electrical signal is 7, then the second electrical signal corresponding to 7 is output, and the feedback component 108 is controlled to perform a feedback action according to the second electrical signal; when the result outputs that the fatigue level corresponding to the first electrical signal is 9, then the second electrical signal corresponding to 9 is output, and the feedback component 108 is controlled to perform an extreme feedback action according to the second electrical signal.

The corresponding relationship between the mild, moderate, extreme, and normal feedback actions and the second electrical signal may be preset in the processing chip 107 in advance.

According to an embodiment of the present invention, as shown in FIG. 1 and FIG. 2 , the headrest frame 104 is located between the headrest outer panel 105 and the plane formed by the slide bar 103 itself.

That is to say, the headrest frame 104 is clamped by the plane formed by the headrest outer panel 105 and the slide bar 103 itself, so that the processing chip 107 located on the headrest frame 104 can be protected from being squeezed.

In another embodiment, as shown in FIG. 1 and FIG. 2 , the seat headrest 100 further includes:

The headrest inner panel 113 has one side overlapped and fixed on the first connection part to form a second connection part. The headrest inner panel 113 is used to wrap the headrest frame 104 and the processing chip 107; one side of the headrest outer panel 105 is overlapped and fixed on the second connection part.

As shown in Fig. 1 and Fig. 2, a hat-shaped wrapping portion can be provided on the upper part of the headrest inner panel 113, which can be directly covered on the first connection portion, and then one side of the headrest outer panel 105 is overlapped and fixed on the second connection portion in an arc shape, that is, the side surface of the headrest outer panel 105 close to the headrest inner panel 113 can be glued and connected with the side surface of the headrest inner panel 113 close to the headrest outer panel 105. A hat-shaped wrapping portion can also be provided on the lower part of the headrest inner panel 113 to wrap the processing chip 107 and the headrest frame 104, which can strengthen the overall structural strength to protect the processing chip 107 from being squeezed.

According to one embodiment of the present invention, as shown in FIG. 1 and FIG. 2 , the feedback component 108 includes: a vibration component 1081 located between the headrest inner panel 113 and the headrest outer panel 105 , and configured to drive the headrest outer panel 105 to vibrate according to the second electrical signal.

Wherein, the vibration component 1081 can be a micro vibration motor, and the micro vibration motor has different vibration modes for different second electrical signals. Wherein, the headrest inner panel 113 and the headrest outer panel 105 are connected by a micro vibration motor. For example, when the fatigue level represented by the second electrical signal is 0, the vibration component 1081 does not vibrate; when the fatigue level represented by the second electrical signal is 4, the vibration mode of the vibration component 1081 is continuous vibration for a preset time (for example, 3s); when the fatigue level represented by the second electrical signal is 7, the vibration mode of the vibration component 1081 is intermittent vibration for a preset time (for example, vibration for 1s, pause for 0.5s, and a total of 5s); when the fatigue level represented by the second electrical signal is 9, the vibration mode of the vibration component 1081 is continuous vibration (for example, vibrating at the same vibration frequency all the time, or vibrating in an intermittent vibration mode all the time (for example, vibrating for 2s, pause for 0.3s, and continuing all the time)).

According to one embodiment of the present invention, as shown in FIG. 1 and FIG. 2 , the feedback component 108 includes: a buzzer 1082 or an electric horn 1082 , located at one end of the headrest frame 104 adjacent to the seat back, for issuing a warning sound according to the second electrical signal.

It is understandable that the buzzer 1082 or the electric horn 1082 has different chirping modes for different second electrical signals. For example, different feedback actions may be provided for different second electrical signals. For example, when the fatigue level represented by the second electrical signal is 0, the buzzer 1082 or the electric horn 1082 does not make a sound; when the fatigue level represented by the second electrical signal is 4, the buzzing mode of the buzzer 1082 or the electric horn 1082 is continuous buzzing for a preset time (for example, 3 seconds); when the fatigue level represented by the second electrical signal is 7, the buzzing mode of the buzzer 1082 or the electric horn 1082 is intermittent buzzing for a preset time (for example, buzzing for 1 second, stopping for 0.5 seconds, and lasting for a total of 5 seconds); when the fatigue level represented by the second electrical signal is 9, the buzzing mode of the buzzer 1082 or the electric horn 1082 is continuous buzzing (for example, buzzing all the time, or buzzing in an intermittent buzzing mode (for example, buzzing for 2 seconds, stopping for 0.3 seconds, and continuing all the time)). Among them, the corresponding relationship between the buzzing mode and the second electrical signal corresponding to different fatigue levels is preset in advance in the processing chip 107.

In other embodiments, the feedback component 108 includes both a buzzer 1082 or an electric horn 1082 and a vibration component 1081. When the fatigue level represented by the second electrical signal is 0, the buzzer 1082 or the electric horn 1082 does not make a sound, and the vibration component 1081 does not vibrate; when the fatigue level represented by the second electrical signal is 4, the buzzer 1082 or the electric horn 1082 chirping mode is continuous chirping for a preset time (for example, 1 second), and the vibration mode of the vibration component 1081 is continuous vibration for a preset time (for example, 3 seconds), and the two can be performed simultaneously or successively; when the fatigue level represented by the second electrical signal is 7, the vibration component 1081 The vibration mode is an intermittent vibration preset time (for example, vibrate for 1s, pause for 0.5s, and last for a total of 5s), and the chirping mode of the buzzer 1082 or the electric horn 1082 is a continuous chirping preset time (for example, chirping for 3s). Similarly, the two can be performed simultaneously or successively; when the fatigue level represented by the second electrical signal is 9, the chirping mode of the buzzer 1082 or the electric horn 1082 is a continuous chirping (for example, chirping all the time), and the vibration mode of the vibration component 1081 is a continuous vibration (for example, vibrating all the time at the same vibration frequency, or vibrating all the time in an intermittent vibration mode (for example, vibrating for 2s, pausing for 0.3s, and continuing all the time)). Other configurations can also be set, and the present invention does not impose specific restrictions on this. It is sufficient to follow the principle that the higher the fatigue level, the stronger the chirping intensity and the vibration intensity.

According to one embodiment of the present invention, as shown in FIG. 3 , a speaker cover 110 is provided at one end of the headrest outer panel 105 adjacent to the seat back, which is in contact with the buzzer 1082 or the electric horn 1082 . The speaker cover 110 is used to accommodate the buzzer 1082 or the electric horn 1082 and is also used for sound amplification.

Optionally, the biosensor 106 may be a brain wave sensor.

Among them, the brain wave sensor can collect the user's brain wave signals, electrocardiogram signals, electromyogram signals and electrooculogram signals. Since the brain wave signal can better reflect the driver's fatigue level than the electrocardiogram signal, electromyogram signal and electrooculogram signal, the electrocardiogram signal, electromyogram signal and electrooculogram signal collected by the brain wave sensor are filtered out, leaving only the brain wave signal to reflect the driver's fatigue level.

FIG6 is a block diagram of a vehicle according to an embodiment of the present invention. As shown in FIG6 , the vehicle 200 comprises: the seat headrest 100 as described above; the seat headrest 100 is installed on the seat back; the slide bar 103 is retractably connected to the seat back;

Also includes: a vehicle controller 114 and a display screen 115;

The vehicle controller 114 communicates with the processing chip 107 , and the vehicle controller 114 is used to control the display screen 115 to display corresponding warning information according to the second electrical signal generated by the processing chip 107 processing the first electrical signal.

As shown in Fig. 1 and Fig. 2, a slide bar positioner 112 may be provided on the slide bar 103, so that the position of the seat headrest 100 can be adjusted by extending and retracting the slide bar 103 between the seat backs to accommodate drivers of different heights.

The vehicle controller 114 and the processing chip 107 can communicate with each other via Bluetooth, WIFI, wireless radio frequency and other communication methods.

That is to say, when the processing chip 107 generates the second electrical signal, it is also sent to the vehicle controller 114, and the vehicle controller 114 controls the display screen 115 to display the corresponding warning information according to the second electrical signal corresponding to the fatigue level. Among them, the display screen 115 can be a vehicle-mounted display screen 115, and the display screen 115 can display different colors according to different fatigue levels. For example, when the fatigue level represented by the second electrical signal is 0, the display screen 115 can display green; when the fatigue level represented by the second electrical signal is 4, the display screen 115 can display yellow; when the fatigue level represented by the second electrical signal is 7, the display screen 115 can display light red; when the fatigue level represented by the second electrical signal is 9, the display screen 115 can display dark red. Therefore, by displaying different colors of the vehicle-mounted display screen 115, the driver or other people in the car can be visually impacted, and then the driver's driving status can be prompted. When the fatigue level is high, take a proper rest to ensure safe driving.

According to one embodiment of the present invention, the processing chip 107 is also used to receive and process the third electrical signal, and send a start-up assisted driving system signal to the vehicle controller 114 based on the processed third electrical signal and the abnormal sample model. The vehicle controller 114 controls the start-up assisted driving system based on the start-up assisted driving system signal.

Among them, the third electrical signal can be a heart rate pulse signal, and the abnormal sample model is a heart rate of less than 60/min, or greater than 90/min; within this range, the vehicle controller 114 controls the assisted driving system to start according to the assisted driving system start-up signal to avoid danger when the driver is unwell.

FIG7 is a flow chart of a fatigue level detection method proposed in an embodiment of the present invention. The method is implemented based on the vehicle involved in the previous embodiment. As shown in FIG7 , the detection method includes the following steps:

S101, receiving a biological signal of a driver collected by a biological sensor, and generating a first electrical signal according to the biological signal;

Among them, the biosensor can collect the user's brain wave signals, electrocardiogram signals, electromyogram signals and electrooculogram signals. Since the brain wave signals can better reflect the driver's fatigue level than the electrocardiogram signals, electromyogram signals and electrooculogram signals, the electrocardiogram signals, electromyogram signals and electrooculogram signals collected by the brain wave sensor are filtered out, leaving only the brain wave signals to reflect the driver's fatigue level.

S102, processing a first electrical signal;

Wherein, processing the first electrical signal includes: performing noise reduction processing on the first electrical signal;

It should be noted that the first electrical signal includes brain wave signals and electrooculogram, electromyogram, electrocardiogram, noise and AC interference signals, and the acquisition range is 0 to 200 Hz. As shown in Figure 8, the Butterworth linear filter is first used to perform initial processing on the acquired signal to remove the AC interference signal. Then a high-pass filter with a cutoff frequency of 1 Hz is used to eliminate low-frequency components, and a low-pass filter with a cutoff frequency of 50 Hz is used to eliminate high-frequency components. Finally, a wavelet decomposition linear filter is used to remove electrooculogram, electromyogram, and electrocardiogram interference signals similar to the EEG signal. Signals with a band of 12 to 25 Hz, 6 to 12 Hz, and 3 to 6 Hz are left for EEG signal reconstruction and analysis.

S103, generating a second electrical signal according to the processed first electrical signal and a preset fatigue level model;

The processed first electrical signal only includes signals in the bands of 12-25 Hz, 6-12 Hz, and 3-6 Hz. After reconstructing the brain wave signals in these bands, a second electrical signal corresponding to the fatigue level of the first electrical signal can be output based on a preset fatigue level model.

As shown in FIG9 , the steps for establishing the preset fatigue level model are as follows:

S01, dividing the driver's fatigue levels into multiple levels according to the driver's brain wave frequency range and the driver's corresponding physical condition;

First, the relationship between fatigue status and brain wave change characteristics was clarified, as shown in Table 1.

Table 1 Relationship between fatigue status and brain wave change characteristics

Next, the brain waves that need to be obtained to detect changes in fatigue status are mainly theta waves, alpha waves, and beta waves. The relationship between various brain wave waveforms and the human body status of adults is shown in Table 2.

Table 2 Relationship between various EEG waveforms and human body conditions

Finally, the fatigue model is established.

The fatigue evaluation index divides the fatigue into 9 levels, 0 for no fatigue, 9 for extreme fatigue and deep sleep; 7 for fatigue state, set as the critical level that is prone to accidents; 4 for mild fatigue state, set as the rest prompt level. As the driving time increases, the relationship between fatigue and driving time is shown in Figure 10, where the black points in Figure 10 represent the fatigue level at the corresponding driving time.

S02, establishing a brain wave signal power spectrum density feature matrix for each fatigue level.

That is, the power spectrum density characteristic matrix of the brain wave signal is established in advance for each fatigue level.

It can be understood that step S103 generates a second electrical signal based on the first electrical signal and the preset fatigue level model, including: calculating the power spectrum density of the first electrical signal after noise reduction processing, and obtaining the characteristic matrix of the first electrical signal; (i.e., performing Fourier transform on the frequency domain characteristics of the sampled brain waves, extracting the power spectrum density of the signal, establishing a characteristic matrix, and recording the brain wave change rules and intervals). Obtaining the similarity weights of the power spectrum density characteristic matrix of the brain wave signal corresponding to each fatigue level in the preset fatigue level model and the characteristic matrix of the first electrical signal; outputting a second electrical signal of the fatigue level corresponding to the first electrical signal according to the similarity weight.

It should be noted that a brain wave signal power spectral density characteristic matrix is pre-established according to the fatigue level. After processing the first electrical signal, the power spectral density of the first electrical signal is obtained, and then the characteristic matrix of the first electrical signal is obtained. Then, the similarity weights of the characteristic matrix of the first electrical signal and the power spectral density characteristic matrices of each brain wave signal are calculated. The fatigue level represented by the brain wave signal power spectral density characteristic matrix corresponding to the highest weight is the fatigue level reflected by the characteristic matrix of the first electrical signal.

For example, the characteristic matrix of the power spectrum density of the brain wave signal is _Ti = [ti _{, 1} , _{ti, 2} , ... _{ti, n} ], and the characteristic matrix of the first electric signal is _Tj = [ _{tj, 1} , _tj , 2, ... _{tj, n} ], i represents the preset fatigue level, and j represents the acquisition signal. The similarity weight between _Ti = [ti _{, 1} , _{ti, 2} , ...ti _{, n} ] and _Tj = [ _{tj, 1} , _{tj, 2} , ... _{tj, n} ] is calculated, and _αij is used to represent the weight of the similarity for , thereby obtaining the matrix A = ( _αij ) composed of _αij , the larger the value of the maximum eigenvector _λmax of the matrix, the higher the characteristic line weight, and the more the sampled brain wave _Tj conforms to the fatigue brain wave characteristics.

It should be explained that the above maximum eigenvector λ _max and n can be used to calculate the consistency index, index (n is the dimension of matrix A) to adjust the sensitivity of fatigue recognition. Taking the sample model of 4-level fatigue state as an example, μ=0.3 (preferably), when the sampled brain wave A is identified as fatigue, as shown in Figure 11. When μ=0.6 is set, the sampled brain wave B is identified as fatigue, as shown in Figure 12. Therefore, when the consistency index value is larger, the brain wave similarity is also greater, and the sensitivity is reduced.

It should also be noted that, in order to simplify the model and avoid generating the feature matrix T _j = [t _{j, 1} , t _{j, 2} , ... t _{j, n} ] after each sampling, similarity weight calculation is performed with the power spectral density feature matrices of all fatigue levels. It can be set in advance that within 0-2 hours of driving, similarity weight calculation is performed only with the power spectral density feature matrices of 0-4 fatigue levels, within 2-6 hours, similarity weight calculation is performed only with the power spectral density feature matrices of 4-7 fatigue levels, and beyond 6 hours, similarity weight calculation is performed only with the power spectral density feature matrices of 7-9 fatigue levels.

Therefore, after calculating the similarity weight, a fatigue level close to the first electrical signal is output according to the weight, and then a corresponding second electrical signal is output according to the fatigue level.

S104, controlling the feedback component to generate a corresponding feedback action according to the second electrical signal.

For example, when the brain wave is identified as a fatigue state of level 4, a wake-up signal is triggered. The wake-up signal is converted and amplified, the input voltage is 5V (first electrical signal), the output voltage is 3V (second electrical signal), and the feedback component (micro vibration motor and buzzer or electric speaker) performs corresponding feedback actions according to the second electrical signal (the specific content has been detailed in the previous embodiment and will not be repeated here).

The seat headrest proposed in the embodiment of the present invention is more comfortable than the brain wave detection devices (mostly helmets) currently on the market, and increases the space inside the car without affecting the driver's field of vision and flexibility of movements such as turning the head. In addition, the seat headrest collects and processes brain wave signals, is small in size and low in cost.

In other embodiments, the processing chip 107 can also record the driver's heart rate and pulse signals, and the processing chip 107 stores a preset heart rate threshold, such as a range of approximately 60-90. If it is lower than 60 or higher than 90, it can be considered that the driver has an abnormal physical condition, and a signal to start the assisted driving system can be sent to the vehicle controller to start assisted driving to avoid dangerous situations.

Therefore, the seat headrest proposed in the embodiment of the present invention is an intelligent headrest for automobile seats that recognizes driving status based on the collection of biological information such as brain waves of the driver. When the driver is identified as fatigued driving, the intelligent headrest can send wake-up signals such as vibration and sound. When the driver is identified as having other abnormal conditions, such as tachycardia, fainting, shock, etc., the intelligent headrest can warn the driver and send auxiliary driving signals to the vehicle system. The seat headrest is a commodity, not limited by the vehicle model and configuration, and is easy to disassemble and assemble, and the user can use it freely. It makes up for the singleness of the detection products on the market that rely on identifying facial or eye features to determine whether the driver is tired, because some drivers will not show fatigue in facial features even if they are tired, but the waveform of brain waves will have different performances, thereby improving driving safety. Functions can be set and controlled through the intelligent vehicle system, which is convenient to use. The integrated processing chip is small in size and can be fully assembled inside the headrest without affecting the space inside the car. In addition, the biological information collection method does not affect the user's driving habits and has good comfort.

In summary, according to the seat headrest, vehicle and fatigue level detection method proposed in the embodiment of the present invention, the seat headrest includes: filling sponge, headrest skin, slide rod, headrest frame, headrest outer panel, at least one biosensor, processing chip and feedback component, the side of the headrest frame away from the seat back is fixedly connected with the end of the slide rod away from the seat back to form a first connection part, and the other end of the slide rod is connected to the seat back; one side of the headrest outer panel is overlapped and fixed on the first connection part, and the other side of the headrest outer panel naturally droops; at least one biosensor is arranged on the side surface of the headrest outer panel away from the headrest frame, contacts the driver's head, is used to collect the driver's biological signal, and outputs a first electrical signal corresponding to the biological signal; the processing chip is configured on the headrest frame, is used to receive and process the first electrical signal, and generates a second electrical signal corresponding to the fatigue level based on the preset fatigue level model and the first electrical signal; the feedback component is electrically connected to the processing chip, and the feedback component is used to make a corresponding feedback action according to the second electrical signal. In order to accurately monitor the driver's fatigue level.

It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (11)

1. A seat headrest comprising: filling sponge, headrest skin and sliding rods; characterized by further comprising:

The headrest framework is fixedly connected with one end, far away from the backrest, of the slide rod to form a first connecting part, and the other end of the slide rod is connected with the backrest;

a headrest outer panel, wherein one side of the headrest outer panel is fixedly connected to the first connecting part in a lap joint manner, and the other side of the headrest outer panel naturally sags;

at least one biosensor arranged on a side surface of the headrest outer panel away from the headrest framework, contacting the head of the driver, for collecting biological signals of the driver, and outputting first electric signals corresponding to the biological signals;

The processing chip is configured on the headrest framework and is used for receiving and processing the first electric signals and generating second electric signals corresponding to fatigue levels based on a preset fatigue level model and the first electric signals;

The feedback component is electrically connected with the processing chip and is used for making corresponding feedback actions according to the second electric signal;

the sliding rod comprises a U-shaped sliding rod part with gradually widened opening and a part which is mutually parallel to contact with the seat back, and a certain angle is formed at the joint of the two parts;

the headrest framework is a U-shaped framework, and the opening end of the U-shaped framework is fixedly connected with the U-shaped bottom of the U-shaped slide bar part with gradually widened opening;

the preset fatigue grade model is divided into nine grades from 0 to 9, and the greater the numerical value is, the higher the fatigue degree is;

After the biological sensor collects the biological signals of the driver and converts the biological signals into the first electric signals, the processing chip processes the first electric signals, compares the first electric signals with the preset fatigue level model, outputs fatigue levels corresponding to the first electric signals, outputs second electric signals corresponding to the fatigue levels, and controls the feedback component to perform the feedback action according to the second electric signals;

the feedback action comprises mild, moderate, extreme and normal, and the corresponding relation with the second electric signal is preset in the processing chip in advance.

2. The seat headrest of claim 1, wherein the headrest framework is located between the headrest outer panel and a plane formed by the slide bar itself.

3. The seat headrest of claim 2, further comprising:

The headrest inner panel is fixedly connected to the first connecting part in a lap joint way to form a second connecting part, and the headrest inner panel is used for wrapping the headrest framework and the processing chip; one side of the headrest outer panel is fixedly connected to the second connecting portion in a lap joint mode.

4. A seat headrest as claimed in claim 3 wherein the feedback means comprises: and the vibration part is positioned between the headrest inner panel and the headrest outer panel and is used for driving the headrest outer panel to vibrate according to the second electric signal.

5. The seat headrest of any of claims 1-4, wherein the feedback member comprises: and the buzzer or the electric horn is positioned at one end of the headrest framework close to the seat backrest and is used for sending out warning sound according to the second electric signal.

6. The seat headrest according to claim 5, wherein a portion of the headrest outer panel abutting against the buzzer or the electric horn is provided with a horn cover for accommodating the buzzer or the electric horn and also for amplifying sound, in close proximity to one end of the seat back.

7. The seat headrest of claim 1, wherein the biosensor is an brain wave sensor.

8. A vehicle, characterized by comprising: a seat headrest as claimed in any one of claims 1 to 7; the seat headrest is mounted on the seat back; the sliding rod is connected with the seat backrest in a telescopic way;

further comprises: the vehicle controller and the display screen;

The vehicle controller is used for controlling the display screen to display corresponding warning information according to the second electric signal generated by the processing of the first electric signal by the processing chip.

9. The vehicle of claim 8, wherein the processing chip is further configured to receive and process a third electrical signal, and send a start-up auxiliary driving system signal to a vehicle controller according to the processed third electrical signal and the abnormal sample model, and the vehicle controller controls start-up of the auxiliary driving system according to the start-up auxiliary driving system signal.

10. A fatigue level detection method, characterized by being implemented on the basis of a vehicle according to claim 8 or 9, comprising the steps of:

receiving a biological signal of the driver acquired by the biological sensor and generating a first electric signal according to the biological signal;

Processing the first electrical signal;

Generating a second electric signal according to the processed first electric signal and a preset fatigue level model;

controlling the feedback component to generate corresponding feedback actions according to the second electric signal; the method comprises the following steps of:

Dividing a plurality of fatigue grades according to the brain wave frequency range of the driver and the corresponding physical state of the driver;

And establishing a brain wave signal power spectral density characteristic matrix for each fatigue grade.

11. The method for detecting a fatigue level according to claim 10, wherein,

Said processing said first electrical signal comprises:

noise reduction processing the first electrical signal;

the generating a second electrical signal according to the first electrical signal and a preset fatigue level model includes:

Calculating the power spectral density of the first electric signal after the noise reduction treatment, and obtaining a feature matrix of the first electric signal;

Acquiring similarity weight of the brain wave signal power spectrum density characteristic matrix corresponding to each fatigue grade in the preset fatigue grade model and the characteristic matrix of the first electric signal;

And outputting a second electric signal of a fatigue level corresponding to the first electric signal according to the similarity weight.