Supervised: modern car security systems
While we read news about self-driving cars, few people think about how quietly the security systems of a modern car are developing. Every year, safety requirements increase: when testing according to Euro NCAP standards, side impacts on a pole were introduced, mandatory ESP is required, more attention is paid to child safety. This changes not only the appearance of the car (minimizing sharp corners and edges in the front of the car, the appearance of gentle and rounded hoods), but also the development of "active safety" systems designed to prevent accidents at all. Let's find out how much the “modern car” sees and knows ”about the world around it.
Regardless of how each manufacturer calls these systems, the essence of them is to monitor either the surrounding area (detection of possible obstacles in front of the car) or the driver (systems that control driver fatigue, the presence of fastened seat belts) or the state of the road surface (control of the road marking, weather conditions).
An example of such a security system is Volvo City Safety, which began in 2007. This automaker has set a very ambitious goal - by 2020, people in Volvo cars should not die in traffic accidents. Surely, reality will adjust these plans, however, existing developments are already able to please both beginners and experienced drivers.
To monitor the situation on the road in the car, the LIDAR sensor (Light Detection And Ranging) is used, which is installed in the upper part of the windshield at the rear-view mirror. The lidar emits electromagnetic waves to the object and receives a return signal - an echo. The speed of the car in front is estimated by the change in the frequency of the reflected wave, and the distance to the car - by the time the signal returns. Lidar uses an infrared laser beam. The principle of action of a lidar is similar to a radar. Laser sensors are cheaper than radars, but are influenced by weather conditions, which is why premium cars use mainly radars. The distance sensor is mounted on the front bumper or grille of the vehicle’s radiator. The range of the sensor is about 150 meters. Modern cars use short and long range distance sensors.
The system analyzes the possibility of a collision and in case of danger gives a command to apply the brakes and stop the car. At speeds up to 50 km / h, the system is able to work at a distance of 50 meters, and with slow movement (up to 15 km / h) it can completely stop the car. If the vehicle speed is higher, then it will be reduced as much as possible, to reduce possible damage during an accident. It is curious that the sensor itself has as many as three “lenses,” one for operation and the correct determination of the distance is not enough. There are many options for pedestrian detection systems - these are TRW Advanced Pedestrian Detection System and Subaru, BMW Night Vision, Honda Sensing, Ford Pre-Collision Assist, Toyota Night View, Mercedes PRE-SAFE and many others.
In addition to the automatic braking system itself, this security system also includes a camera with the ability to recognize traffic signs, cyclists and pedestrians, a system for monitoring the situation behind the car and assistance when reversing with poor visibility. BMW went further in this direction by introducing an intelligent night vision system for detecting pedestrians dangerously close to the roadway. The Dynamic Light Spot system using heart rate sensors detects the presence of living creatures at a distance of up to 100 m from the machine. The methods of operation can also be different - in addition to alerts or automatic braking, a brake booster system can also be used. If the obstacle turned out to be real and the driver presses the brake, the car will be ready to brake harder.
Traffic sign recognition usually takes place according to the following algorithm:
- recognition of the shape of a road sign (round shape);
- recognition of color of a sign (red color on white);
- label recognition (speed value);
- recognition of the information plate (mode of transport, time of action, coverage area);
- analysis of the actual speed of the car;
- comparison of the vehicle speed with the maximum allowable speed;
- visual and audible warning of the driver in case of deviation.
An image in the form of a speed limit sign is displayed on the instrument panel screen and remains visible until the limit is over or is changed. In a number of designs of the road sign recognition system, the electronic unit interacts with the navigation system, namely, it uses data on speed limit signs from navigation maps in its work. Even if the mark is not detected by the camcorder, information about it will be displayed on the instrument panel. The system is capable of recognizing speed limits that apply to a particular mode of transport, as well as signs that speed limits are canceled.
Another interesting feature in cars of various manufacturers is the tracking system for marking on the road LDW (Lane Departure Warning). This system monitors the markings on the road and signals the driver if the car leaves its lane without turning signals on. The classic response of the LDW system to the intersection of the marking line is an audible signal and a blinking indicator to alert the driver. The system recognizes intermittent and continuous marking, works day and night. Of course, when the road is covered with snow, the camera will not be able to see the markings, and when the markings are completely erased, the system does not work as expected: it’s quite logical that the camera just doesn’t catch on anything. Cameras for such a system are located in a "classic" place for DVRs - near the rear view mirror, just below the working area of the "wipers".motion detector, navigator and audio headset . More complex systems use the ESP (Electronic Stability Program) braking system, which can brake each wheel individually. In this case, if the car crosses the markings on the right side, the wheels on the left are braked, which shifts the vehicle's trajectory to the center of the strip.
With the help of external sensors, HBA (High Beam Assist) headlight dimming and driving systems are also used. In addition to actually switching the light mode, using data from the LIDAR sensor, the system can adjust the lighting parameters depending on road conditions (change the light spot). Many cars are equipped with cameras around the perimeter, providing the functions of all-round visibility, when the car can be observed when viewed from above and around it the image from all cameras is drawn at once. To increase security, the MOD (Moving Object Detection) system is used, which is designed to control the presence of moving objects in the camera's field of view. When the system is activated and someone passes near the car, a sound signal is given and the image from the camera, which recorded the movement, is highlighted with a frame.
The car also learned to monitor driver fatigue. Control of driver fatigue DAS (Driver Attention Support) includes the collection of a number of parameters, based on which a conclusion is made about the level of driver fatigue. If the system considers the driver to be tired, it will give a signal and advise you to drink a cup of coffee (some systems use the coffee cup icon to display the driver’s “fatigue band”). Such systems process several sources of information, on the basis of which they draw their conclusion. There are solutions that monitor the face and facial expressions of the driver using the cabin camera. They are able to track the direction of the driver’s gaze, how long he closes his eyes, the position of his head. Closest to solving the problem is Ford, which offers a system for assessing the load of the driver,
Driver fatigue is evaluated by processing many parameters:
- vehicle movements (speed, longitudinal and lateral acceleration, yaw rate);
- biometric indicators (heart rate, respiratory rate, skin temperature).
- driver actions (steering angle, position of the accelerator and brake pedals);
- road conditions (traffic density, nature of the road surface);
The following biometric sensors are used in the driver load assessment system:
- infrared sensor behind the steering wheel that monitors the temperature of the face.
- piezoelectric sensor in the seat belt for monitoring the respiratory rate;
- conductive pads on the steering wheel rim for measuring heart rate;
- infrared sensors on the rim of the steering wheel for measuring the temperature of the palms;
Another area of use of biometric sensors is related to monitoring the physical condition of drivers. Ford offers control over the age of drivers using heart rate sensors integrated in the seat. It is based on the technology of an electrocardiogram, which monitors cardiac electrical impulses and timely detects disorders, as well as symptoms of other diseases.
Toyota uses sensors on the steering wheel rim to monitor vital signs: electrodes for heart rate monitoring and optical sensors for evaluating palm conductivity. The driver’s condition monitoring system is connected to the emergency braking system, which allows you to stop the car in case of a heart attack, as well as a navigation system that automatically paves the way to the nearest medical institution. The system allows you to determine the onset of a heart attack in the early stages.
BMW is working on a technology to warn drivers with diabetes about high blood sugar. A device for measuring blood sugar is connected to a smartphone, which in turn is connected via Bluetooth to the car multimedia system. Information is displayed on the system screen warning the driver about the danger of losing consciousness due to elevated blood sugar levels.
Already in 2016, Volvo promises to put into operation a communication system between car safety systems on the road. This is a system of "cloud" storage of data collected by cars, from where other cars and utilities remove it. How much such information can be useful can easily be estimated using the Yandex.Tracks application example. By pre-installing a similar system on all cars and collecting much more data, except for the location and speed, it is possible to prevent accidents, to notify utilities about complex (icy) sections of the road.
Today, these systems have become available in popular and relatively affordable cars: usually, such technologies are found singly and in much more expensive cars. Almost imperceptibly, cars learned to monitor both the external environment and their own passengers. In emergency situations, they have already learned to take control, to control the driver - the future is closer than it seems at first glance. However, car drivers without these functions are still too early to seriously worry - if necessary, they can install some of these systems on their own: for example, instead of a camera system around the perimeter, you can install parking sensors, for video recording the situation in front of the car and in the passenger compartment - a DVR with two cameras, for operational control for biometric indicators - a smart watch with a heart rate monitor.
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