Driver fatigue recognition system how it works. If you are tired, you need to rest - the DAS system will remind you of this. How does the driver fatigue monitoring system work?

• Dubinin Alexander Alexandrovich, bachelor, student
• Volzhsky Polytechnic Institute
• Moiseev Yuri Igorevich, Candidate of Science, Head of the Department
• Volgograd State Technical University, Volzhsky Polytechnic Institute (branch)

• SIGNAL
• FATIGUE
• DRIVER
• FATIGUE DETECTION SYSTEM

This article discusses the driver fatigue detection system. A solution for the modernization of equipment is proposed that can eliminate the existing problem.

• Features of the use of tachographs in the control system of passenger vehicles
• Development of methods for adapting the workflow of a diesel engine to run on compressed gas
• The possibility of installing a turbocharger on a passenger car engine
• Development of a data transmission system about bus malfunctions using a tachograph in order to reduce the repair time

We all know perfectly well that on the road the driver is the main figure in traffic, I compare such components as "road" and "car", for the most part accidents are caused by the driver, namely two thirds of all car accidents. One of the reasons is the psychophysiological state of the person driving. Of course, experienced drivers know the everyday tricks of how to cheer themselves up before traveling a long distance and during their journey. But often all these techniques work no more than 4 hours, and if you are also driving alone, for example, somewhere in another city, where you have to be behind the wheel for more than 12 hours. Knowing for itself, a monotonous road, flickering trees, all this affects the attention, reaction of the driver. It is worth noting that drivers who fall asleep at the wheel are the cause of 25% of car accidents. Of course, everything cannot be reduced to just one driver and his condition. Road conditions, vehicle malfunctions, traffic light breakdowns. But still, I would like to return to the state of the driver.

After analyzing the market for cars and technologies that keep pace with them, there are special systems for determining driver fatigue. The driver's fatigue control system monitors his psychophysiological and physical condition of the driver, when a deviation from the norm by the specified system is detected when analyzing the movement, the SOUV informs the driver that he needs to stop or rest. There are three main systems for recognizing fatigue: a system for determining driver fatigue, a system for monitoring biometric parameters of the body, and a system for tracking exacerbations of chronic diseases.

Their purpose is to inform the driver about his fatigue. There are many such devices and they all work in different ways. There are SOUV devices that, when deviating from the driver's standards, inform him with sound and light signals, physical, namely, after identifying a danger, for example, the seats begin to vibrate. There are systems that, again in the event of a deviation from the driver's standards, take control of the car and work in an autonomous mode. The operation of the driver fatigue detection system is shown in “fig. one".

Figure 1. Operation of the driver fatigue detection system

Most of the devices for the driver's fatigue detection system work autonomously and are not connected with the vehicle's BMU.

These devices are easily connected to the car. There are systems that are installed in front of the driver, giving sensory signals, monitoring the state of a person, his head position, his eyelids and pupils, as well as video surveillance systems.

There are SAUs that have contact directly with the person himself, namely, a bracelet that is worn on the arm and controls its condition using the heart rate and body temperature.

A device called Stopsleep., Which monitors a person's condition using sensors that read information on the conductivity of the skin.

All these devices, if the driver deviates from the norm, inform him about this, but apart from signals and light, the device does not apply any actions in relation to the car.

In connection with this problem, I would like to make changes that would affect the operation of devices that are not related to the vehicle's BSU.

Consider the example of a tachogrof, Atol Drive 5.

This device supports both wired and wireless technology for transmitting data to processing and control modules.

"TCA-02NK" produced by CJSC "Izmeritel-Avto".

Violations are recorded and warnings are displayed about various violations (speed limit, excess of labor time, total driving time per day, operation of chip cards and much more). The built-in printer allows you to print all parameters on thermal paper, and the information display will display the same information for your reference. "Drive 5" is produced by ATOL.

An example is shown in “fig. 2 "

Advantages: the presence of a cover on the device for quick replacement of the SKZI and the battery; allows you to minimize equipment downtime during maintenance; 10 colors and brightness of the backlight that can be adjusted by the driver himself; optimal design of the printing mechanism - the printer has the highest printing speed among the devices on the market; support for working with 2 sim cards; expansion slot, universal solution for interfacing with other on-board devices.

The main purpose of the tachograph is to prevent dangerous accidents caused by the driver. Thanks to such a device, the driver will not exceed the speed limit and will not sit behind the wheel in a tired state.

We decided that it was necessary to improve the tachograph, namely the algorithm of its operation. Let's consider the algorithm of the system.

Let's describe how the modernized tachogrof model works, connected together with an infrared sensor that reads the size of the driver's pupil. The principle of operation is shown in Fig. 3.

After turning on the ignition, the electronic control unit transmits the tachogrof to start the system check. After checking the system and starting the movement of the car, the fatigue detection system, namely the infrared sensor, is activated.

When the sensor detects that the driver has deviated from the norm, it sends a signal to the dispatcher that the driver is falling asleep. Then the dispatcher takes measures to eliminate this problem.

We analyzed the Algorithm of the standard tachogrof and made changes to it, which subsequently increase the safety on the road, the driver himself, passengers and participants in all road traffic.

Based on the information I have collected on the SAWS, it can be noted that the development in this industry does not stand still. Scientists and developers are trying to protect the driver with various systems, but let's not forget that after all, a person drives a car and safety on the road depends on him. I would like every driver to treat his profession with responsibility and clearly understand that sitting behind the wheel in his hands is not only his life, but also the life of passengers.

Bibliography

1. Driver fatigue detection systems. Suslinnikov A. [Electronic resource].
2. http://systemsauto.ru/active/drowsiness_detection_system.html
3. A device called Stopsleep [Electronic resource] .- http://savepearlharbor.com/ (date of treatment 02/06/2017).
4. Tachograph: brands and models [Electronic resource]. - URL: http: postebor.ru/taxografy/cifrovye-taxografy/taxograf-continental-vdo-dtco-3283/ (date of treatment February 6, 2017).
5. Moiseev Yu.I., Popov A.V., Rybanov A.A., Surkaev A.L. // Improving road safety by introducing a self-learning system for determining driver fatigue on a vehicle // article in a magazine // Motor transport enterprise. - 2016 S. 5-8
6. Izustkin A.E., Poluektov M.V., Moiseev Yu.I. // Improving the efficiency of operating vehicles equipped with tachographs // article in the proceedings of the conference. - 2016 P 171-172

DAC and Attention Assist fatigue control systems monitor the physical condition of the driver and, if necessary, signal that it is time for the driver to stop and rest. Such a check is carried out by three control options:

Attention Assist and DAC are fatigue control systems that monitor the driver's ability to physically control the vehicle and, if necessary, give a signal to stop driving for rest. The check is carried out by three types of control, which depend on the following behavioral factors:
1. Driver behavior is assessed;
2. The driver's gaze is fixed;
3. The movement of the vehicle is monitored.

The Attention Assist device, which monitors the driver's behavior, has been produced by Mercedes-Benz since 2011. This device is guided by the following motivations: way of driving, steering, driver's actions while driving and some other parameters.
Schematically, the fatigue monitoring system consists of a steering sensor, a control indicator and an audible alert that alerts the driver.

A sensor mounted on the steering wheel monitors the change in the force exerted on the steering wheel as it rotates. The system also takes into account information received from other control sensors: driving stability, braking system, visibility restrictions and engine parameters.
Signals received by the device are processed, defining the following parameters:
but) within half an hour from the beginning of the movement, the speed and lateral acceleration of the vehicle are analyzed (driving style);
b) the condition under which the movement occurs (here both the time of day and the duration of the trip are taken into account);
in) the control of the following units is analyzed: buttons located on the steering wheel and below it switches and the brake system;
G) the force of influence on the steering wheel is analyzed;
e) road surface condition and vehicle behavior while driving (lateral and longitudinal acceleration).
By analyzing all these parameters, the system detects violations in the actions of the driver and changes in the direction of the vehicle. After that, a signal with sound accompaniment is sent to the screen located on the dashboard, so that the driver stops to rest. If the driver in a drowsy state ignores the signal and continues driving, the system continues to remind him of this every 15 minutes. It should also be recalled that control over the driver's condition begins to work at a speed of more than 80 km / h.

At Volvo, the driver's control Driver Alert Control (or DAC) differs from Attention Assist in that it monitors only the trajectory of movement along the highway, and video monitoring, following in the direction of the vehicle's path, determines its location in the lane of the roadway. If suddenly the car starts to move beyond the established limits, the system reacts to this as if the driver is tired and issues two warning signals: "soft" and "hard" Both of these signals depend on the general well-being of the driver and differ from each other in volume and tone. The DAC system is activated, working in conjunction with the system elements Lane Departure Warning, when the vehicle speed reaches 60 km / h.

A special built-in unit, which is installed by General Motors, where the already tested Seeing Machines method of assessing the state of the driver's gaze is the base, is installed not only on cars, but also on railway transport. The task of the unit is to monitor the openness of the driver's eyes and their concentration, and when it detects signs of fatigue or loss of alertness and sleepiness, the system immediately gives a command to stop the vehicle.
Also, the driver fatigue tracking system can control other functions of the car, for example, the direction of gaze can be turned on or off certain options on the dashboard. Or, when making a maneuver, notify the driver that he forgot to look in the mirror.

If only tired toys slept, then we would not have heard of any fatigue control systems. Nevertheless, people are also asleep, books, as the song says, are also asleep. At the same time, the statistics are relentless: every year tens of thousands of accidents occur due to the fault of drivers who have fallen asleep at the wheel, and the latest security systems, including technologies that can recognize fatigue in the driver's behavior, are called upon to protect against them.

Research and the first developments in this direction appeared in the 1970s. For example, in 1977, Nissan received a patent from the American bureau entitled "A method for determining the degree of driver fatigue sufficient for safe driving." But in the 80s and 90s, the main attention of industry specialists was focused on less complex, but no less useful systems - such as, that is, systems that take into account the "physics" of the car, and not the "psychology" of the driver. And only when all the juices were squeezed out of them and only the path of their endless long improvement remained, the companies resumed their research in the field of "psychology" with renewed persistence.

But even here not everything is smooth. Some automakers have conventionally become supporters of the school of "behaviorism", while others - "psychoanalysis". The former argue that attention should be paid only to the actions of the driver. The latter want to dig deeper, down to facial expressions and gestures, which are a mirror of a person's inner world. The ranks of the former mainly include European brands and divisions - Audi, Ford, Mercedes-Benz, Volkswagen, Volvo. Japanese companies gravitate towards the latter.

The task set for all systems is the same - to identify a tired or asleep driver and prevent him from doing the irreparable. Volvo was a pioneer in this difficult business, and its production cars were among the first to receive a workable Driver Alert Control system. The central role in it, as in many modern technologies, is given to electronics, which, with the help of a video camera, monitors the movement of the car relative to the road markings. As soon as the system detects that the frequency of steering and yawing exceeds the permissible norm, the driver will be "woken up" by a sound signal, and in addition to this, an icon in the form of a coffee cup will light up on the instrument panel. Thus, the car itself will offer the driver to pause and eat "tweaks".

Video demonstrating the Volvo Driver Alert Control system:

In the late 2000s, Mercedes-Benz also offered its counterpart called Attention Assist. "Mercedes" decided to do without cameras and use only steering wheel and pedal position sensors. In this case, the system analyzed the speed and frequency of steering wheel turns and pedaling. She had little inclinations to adapt to the driver's driving style, but still the pre-installed "portrait" of a vigorous and attentive driver remained the main reference point for her. Then the company taught the system to additionally take into account the time spent by the driver behind the wheel, the frequency of pressing the radio buttons, the climate control system, as well as the influence of external factors - side wind and road surface.

Similar systems are now available for more mainstream models such as the Ford Mondeo and Volkswagen Passat.

Japanese automakers continue to experiment with video cameras that scan facial expressions, blink rate and eye movements. Whose approach is more correct - time will tell. Nonetheless, fatigue monitoring can be useful for drivers who often make long trips, as well as during night travel, when "blankets and pillows are waiting for the guys."

According to statistics, one of the most common causes of car accidents is driver fatigue. Studies have shown that after four hours of driving, the reaction speed, as a rule, decreases by half, and already eight hours of travel show really catastrophic results - a sixfold slowdown in reaction. And since every car manufacturer has always strived to make its products as safe as possible, after the research carried out, the active development of a special sensor that determines the level of driver fatigue began.

The innovators in this area can be considered the Japanese company Nissan, whose specialists, already in 1977, patented a truly revolutionary automotive technology. However, due to active work in other areas, the first working system of this kind was implemented only a few years later.

In fact, Swedish Volvo were the first to use the new technology in practice, installing a system called Driver Alert Control, which included a camera that monitors the behavior of the car on the road, as well as the sensor itself, which measures the frequency and manner of steering wheel movements. The system gave out certain signals when the indicators of steering movements deviated too much from the norm.

Driver Alert Control invites the tired driver to stop and take a break with a cup of coffee

Later, Mercedes joined the two automotive giants. The system has undergone some changes: it was decided to remove the video camera and add a sensor that reacted to the frequency and force of pressing the pedal. In addition, the system was supplemented with indicators indicating certain norms. The sensors worked, giving a signal to stop when these indicators deviated to the maximum from normal. But such a system could not fit every driver. It was later changed somewhat. Sensors were also installed to detect the wind from the side and to assess the quality of the road surfaces. Also, sensors were added to determine the pressing of the buttons of the radio and climate control.

Similar systems are also used on Skoda and Volkswagen vehicles.

Today, the most common and are two types of system implementation. The first case involves a sensor measuring behavior on the road, which includes such characteristics as the force of pressing the brake and gas pedals, as well as the amplitude of the steering wheel movements. This type of system is used by Volkswagen, Mercedes, Volvo and Skoda.

If we talk about the Japanese segment of the market, then a slightly different method is used here. That is why most of all attention is paid to the psychoemotional indicators of the vehicle driver himself. For control, a video camera is used here, which is designed to track the facial expressions and gestures of the driver. First of all, the system is configured to respond when the eyes are closed by responding with a warning signal. It also analyzes how often the driver blinks, how deeply and measuredly he breathes, while recognizing when a person just blinks while driving, and when he closes his eyes.

In general, the system in both cases works in approximately the same way.

To begin with, the control unit collects and analyzes the information received from the cameras and sensors themselves. This approach is intended to significantly expand the capabilities of the system for recognizing existing conditions. After that, a certain driving style of each driver is analyzed and determined in order to subsequently adjust the system to individual parameters. Thus, the received data eventually becomes the established norm in the system.

In the future, the incoming information will be compared with predetermined values ​​of the norms.

The timing of the initial measurement for each brand is purely individual. Typically, the entire procedure takes 15 to 30 minutes.

In the event of a deviation from normal values, the system gives a warning sound signal to the driver, notifying the need to stop.

Doctors argue that not only an excess of information coming from outside, but also its lack contributes to a decrease in a person's working capacity, and, consequently, to the development of fatigue. After all, fatigue is a subjective process from the field of human mental activity. Everyone gets tired the same way, but then they get tired, that is, everyone experiences fatigue differently. Surely, many are familiar with the paradox - after a long joint ride in a car, the passenger gets tired more than the driver, although long-term driving, naturally, leads to greater fatigue of the driver than the inactive passenger. A person in a state of fatigue may not feel tired at all under the influence of emotional arousal, which once again confirms the subjective nature of fatigue. If fatigue is sometimes easy to relieve by talking to a passenger or by loudly playing music, then with fatigue the situation is more complicated. Only good rest will help to bounce back, and even better - sleep. Fatigue of the driver is fraught with an accident. In this state, a person's reaction time increases, attention disorder, weakening of will, drowsiness and other psychophysical disorders occur. An extremely dangerous stage is drowsiness. At its first signs, and this, as a rule - general lethargy, yawning, weakened attention - you should immediately park in a safe place, lean back and sleep, even if for a short time. You will get a noticeable boost of vivacity after 20 minutes of sleep. It is enough for a person to "not get" just one or two hours of sleep at night in order to get behind the wheel with caution. The following factors contribute to increased fatigue: physical stress, smoking, lack of sleep, prolonged wakefulness, taking antidepressants and antihistamines. A person who has not slept for 20 hours is a special risk group. Promotes fatigue and driving at night - until eight in the morning, as well as between 13.00 and 15.00. During these hours, the body's internal rhythm triggers signals of drowsiness.

Doctors argue that not only an excess of information coming from outside, but also its lack contributes to a decrease in a person's working capacity, and, consequently, to the development of fatigue. After all, fatigue is a subjective process from the field of human mental activity. Everyone gets tired the same way, but then they get tired, that is, everyone experiences fatigue differently. Surely, many are familiar with the paradox - after a long joint ride in a car, the passenger gets tired more than the driver, although long-term driving, naturally, leads to greater fatigue of the driver than the inactive passenger. A person in a state of fatigue may not feel tired at all under the influence of emotional arousal, which once again confirms the subjective nature of fatigue. If fatigue is sometimes easy to relieve by talking to a passenger or by loudly playing music, then with fatigue the situation is more complicated. Only good rest will help to bounce back, and even better - sleep. Fatigue of the driver is fraught with an accident. In this state, a person's reaction time increases, attention disorder, weakening of will, drowsiness and other psychophysical disorders occur. An extremely dangerous stage is drowsiness. At its first signs, and this, as a rule - general lethargy, yawning, weakened attention - you should immediately park in a safe place, lean back and sleep, even if for a short time. You will get a noticeable boost of vivacity after 20 minutes of sleep. It is enough for a person to "not get" just one or two hours of sleep at night in order to get behind the wheel with caution. The following factors contribute to increased fatigue: physical stress, smoking, lack of sleep, prolonged wakefulness, taking antidepressants and antihistamines. A person who has not slept for 20 hours is a special risk group. Promotes fatigue and driving at night - until eight in the morning, as well as between 13.00 and 15.00. During these hours, the body's internal rhythm triggers signals of drowsiness.