The Need of Black Box (event Data Recorder) in Automobile Industry

In the recent decade various automobiles became the part of our daily life. As the number of vehicles has grown rapidly, it results in serious issues like improper driving habits, heavy traffic, vehicle condition instability etc. Sometimes it leads to fatal crash causing large amount of causalities. It not only involves loss of life but also loss huge financial loss. These mishaps cannot be totally eradicated but can be reduced to greater extent with the help of Black Box. How it helps the investigation by reconstructing the event before accident, which not only helps investigator to know the actual cause but also helps police to reduce crimes. How medical aid is provided to the passengers who met with an accident in rular area is demonstrated. Application of black box in commercial trucking companies is explained. The main aim of the Black Box is to propose a feasible and useful scenario for public safety.

According to World Health Organization (WHO) more than 1.25 million people are cut short as a result of road traffic crash. Many people loses their life because of remain unattended for long after crash. Around 20-25 million more people suffer non-fatal injuries, with many incurring a disability as a result of the injury. In earlier days due to the absence of the EDR technology in the vehicles many a times a victim is considered to be the offender and the actual cause remains undefined. To address this problem Black Box is introduced in automobile industry, which not only helps the crash investigator to know the actual cause of crash but also helps to propose measures to save lives. First Black Box was introduced in 1974 by General Motors in Air Bag equipped cars called as Sensing and Diagnostic modules (SDMs). It constantly collect and process the car’s acceleration and deceleration. In 1999 General Motors upgraded SDM to include an event data recorder which tracks the car’s speed, engine Revolution Per Minute (RPM), and whether or not brake pedal is pressed, The SDM keeps the record of previous 5 seconds from crash and store it to its onboard memory and, if the airbags are deployed then it saves the most recent five seconds which leads to the actual cause of crash. The European Parliament has passed a law requiring each new car built after 2018 April should be fitted with a system called “eCall”. It is a type of Black Box, which automatically contacts 112-Europe’s single emergency number in the event of crash. It will help to provide the first aid on early basis to the people who met with an accident in remote locations. The data stored in the Black Box should be accessible only to authorized person, so for keeping it secure the stored data on Secure Digital (SD) card is encrypted.

The change in the physical quantity is observed by the sensor which results in sending the output further to connected controller. Controller will read the output of the sensor. The data is stored in SD card. For preventing the data from falsification, encryption algorithm is used and the same data can be accessed by applying decryption algorithm.

The car Black Box is equipped with various types of sensing components which gets activated immediately with earlier possibility of problems which are about to occur. It even gets triggered due to the change in the characteristics or condition like temperature, speed, pressure or applying sudden brake.

Representation of modules and components to be used is done by blocks. It consist of various sensors like brake, seat belt, air bag deployment, accelerometer, ultrasonic, pressure, temperature, light and Global Positioning Satellite (GPS).Various sensor can be connected depending on the sensor connection capability of the processor. All these sensors are connected to CAN module & controller with the help of CAN bus. At the end the event data recorder is used for storing the data, it consists of module for keeping the data in specified format. Microcontroller is the main component of the system. It regulates all the sensors connected to it.

Based on the requirement different kind of processors can be used in the system. ARM7 Processor (Advance RISC machine (Reduced Instruction Set Computer)) is a member of ARM microcontroller family with general purpose 32-bit processor. It provides high performance with low power consumption. Compared ARM7 with many processor, every processor taking multiple cycles for instruction execution.

Control Area Network: It is an Integrated Circuit & single controller based on microchip technology’s device. International Standard Organization (ISO) defined CAN as communication bus basically designed for automotive industry to replace the complex wiring harness with a two wires bus. CAN have high immunity to electrical interface and it can diagnose & repair the data error own its own. The CAN communications protocol, ISO-11898: 2003, shows how information is passed between devices on a network and conforms to Open System Interconnection (OSI) module which is defined as per the layers. Physical layer of the model is used to define actual communication between devices connected by physical medium. The ISO-11898:2003 Standard, the standard 11-bit identifier, provides 125 kbps to 1 Mbps signaling rates. This was later amended with the “extended” 29-bit identifier. The standard 11-bit identifier field provides for 211, or 2048 different message identifiers, whereas the extended 29- bit identifier provides for 229, or 537 million identifiers.

Electronic Sensing Components: Electronic sensing components are considered to be the most important part of the system. Here sensors are our electronic sensing components. The sensors are to be used are explained below:

1. Break: Brake sensor is also called as brake pedal position sensor. It monitors the movement of the brake pedal so that it can directly activate the brake, brake lights, and turn off the cruise control if it is active at that point of time.
2. Seat Belt: To check whether driver whore the seat belt or not a push button is used. Reed switch sensor is used to check the seat belt status at the time of accident or any incident.
3. Air Bag: Deployment of the air bag is triggered by the crash sensors (also known as impact sensors). It is used to detect the frontal impact of the crash and trigger the control unit so that it deploys the air bag to cushion the passenger. Mainly two types of sensors are used for deployment of air bag- Mass type sensor and Roller type sensor.
4. Accelerometer: It is a device which measures the acceleration of the motion of the vehicle. Acceleration force in forward direction is measured by this device. ADXL335 accelerometer is used here which is 3 axis MEMS accelerometer, it measures static and dynamic acceleration.
5. Ultrasonic sensor: For checking the distance between two vehicles either on rear or front, if it approaches too close to the next vehicle then the driver is warned by an alarm.
6. Pressure sensor: The continuous pressure on an object is detected using pressure sensor. It plays a vital role in finding out whether a crash occurred or not. When an object hits a car, this creates a pressure on a vehicle and this value is stored in a system. If the value is above the predefined range of normal then it warn the driver.
7. Temperature sensor: The temperature of the engine is measured using temperature sensor. Many times continuous increase in temperature arise issue. So it is important to keep a record of temperature varying in various conditions.
8. Light: The important lights in the vehicle are flash light, the headlight, rear lights and the brake lights. Light Dependent Resistor (LDR) are used verify whether the lights were functioning properly at the time of the collision.
9. GPS: A GPS system is used to check the co-ordinates of the vehicle, so that in case of accident in remote area the location can be automatically send to the pre stored number using Global system for mobile communication module (GSM).

Working of the System

First of all when the system starts it will initialize all the sensors attached to it. Value of the sensors are continuously monitored and the same is transmitted to the CAN module with the help of the CAN bus. The same data is processed in processor. The change in the values of respective sensors are monitored and even checked against predefined limits of each sensor. If any sensor may or may not exceed its predefined limit, the value will store in the flash memory. If the limit is exceeded by any sensor then it will not only store its value in the flash memory but also starts from the beginning, so that change in the values can be noticed by comparing it with previous one. The data stored in the SD is encrypted so as to keep it safe from falsification.

Analysis of recovered data

The data which was present in the SD card was recovered after the accident. As the data is in encrypted form, decryption algorithm is used to read the data from SD card. In the figure 4 the image of the recovered data in the form of graph viewed in computer is shown. Graph is plotted for different parameter speed (km/hr) against approximate time before event (sec). Different parameters behavior of vehicle speed (Miles Per Hour), engine speed (Revolutions Per Minute/100), throttle position and brake switch (On/Off) are observed. From the report one can easily understand that the accident was not intentional, as the driver immediately applied the brakes at -4 seconds which results gradual decrease in the vehicle, engine speed and even throttle position. There might be a possibility of driver might have slept due to less sleep in routine time, and reacted immediately after seeing that the vehicle moving away from the lane and about to hit another vehicle.

Data recovered from the black box is not only helpful to police and Insurance Company but even helpful to car owner in many ways. The accident which took place in an urban area, which was not caused by you, but because of no eye witness you can’t prove it. Black Box data plays a vital role in these kinds of situation.

Conclusion

This demonstration shows how the Black box collects information from various sensors at different situations and stores the data into a memory unity, which is further helpful in many ways. It can provide more useful information than the physical overview of a crash. The main purpose of this demonstration is to make people aware of how technology plays a crucial part in public safety. This demonstration shows how to utilize a car’s Black Box for car accidents and crime prevention.