In the past two years, various kinds of vehicle-mounted hard disk recorders (DVR) have appeared in the market. As a subdivision market of traditional embedded hard disk recorders, vehicle-mounted hard disk recorders have also attracted the favor of many security enterprises. Vehicle-mounted hard disk recorders inherit the development direction of networking and intelligent technology of ordinary embedded hard disk recorders. In addition, the products of vehicle-mounted hard disk recorders should have GPS satellite positioning function and other customized functions in the transportation industry.
Intelligent Vehicle DVR
But for VHDR, the first thing to do is to narrow and refine the dynamic voltage and current. How to ensure the normal operation of VHDR, stable voltage and current is very important, but on the other hand, the input power of the equipment is fixed. It can be seen from W=U*I that the current changes when the voltage changes, and the direction of the change of voltage and current is always opposite. So if the starting voltage is lower, the relative starting current will increase. Macroscopically, it is so simple, but to achieve this function stably and ensure the normal operation of the equipment, it will take a lot of effort. The first thing to do is to design the protection circuit. We should know that the power board of the car-mounted hard disk video recorder will withstand hundreds of shocks in an hour. If the protection circuit is not well done, the power board will be damaged or the main board will be burned down directly.
Seismic design: Seismic design of vehicle-mounted hard disk video recorders is very important, in fact, how to protect the hard disk. Because the current hard disks are all mechanical spindle hard disks, the distance between the read-write head and the disk surface is only a few microns, if you look at it with the naked eye, the read-write head is attached to the disk surface, but even if you do not understand the hard disk, you should understand that the 5400-turn hard disk rotates at least 90 times per second, if the read-write head is attached to it, it will not take long for the read-write head to wear out. At such close distances, if the seismic performance is not good, as long as the read-write head has a little tremor, the hard disk will be damaged slightly, and the read-write head will crash heavily (hard disk terminology). So the hardware anti-seismic is very important.
Error-tolerant design: Error-tolerant ability of hard disk is a difficult problem that has been solved in both IT hardware industry and software industry since hard disk came into existence. For an embedded system, it is very difficult to achieve a perfect fault-tolerant and error-correcting design. But for the design of embedded system, the purpose of embedded system is to pursue better stability and execution speed, but there is a problem that can not be ignored is the poor portability, which results in that once the design can not be changed too much. So its first design idea is very important. At present, the effective way for embedded system to correct hard disk errors is the ability of read and write control.
Network Application of Vehicle DVR
City bus: It can record the situation happened in the carriage within several weeks, such as pickpocketing, fighting, quarrelling with the company's passengers, seeking redemption disputes, etc. It can also contact the bus advertising company to broadcast the advertisement content of the city's products.
Long-distance bus: It can supervise in-car fraud. Effective control of embezzlement of public funds, such as passenger stopping, private collection of money and goods, can promote the improvement of efficiency, service quality and awareness of transportation companies, and can also provide more intuitive evidence for traffic policemen's behavior of half-way overload.
Accident Record: At present, many cases of car damage and death have not been found out the cause, and the device of traffic record instrument does not function as a "black box" in the true sense. The reason is that the traffic record instrument only records the speed of the car and some brake switches, and the speed of the car is usually recorded as zero km/h when the driver brakes. Direction records are also not recorded when the driver is in emergency with a direction switch. Unable to distinguish between crashes and other accidents, the driver's response to the accident, steering wheel manipulation, front and rear road conditions are very important data to clarify the responsibility of the accident.
Value: or reduce the incidence of bus accidents
Buses, long-distance buses and other passenger service vehicles will be a new scene after the installation of on-board hard disk video recorders.
(1) Traffic and Public Security Bureau staff came to the car where pickpocketing and robbery occurred and replayed the video. The criminal process was clearly reproduced and backed up as evidence. If criminals were found anywhere, they could be arrested at any time, and there was no need to worry about the lack of evidence.
(2) When the traffic policeman gets on the bus for inspection, the playback video can clearly find whether the driver of the car has violated the regulations, whether he has ever been overloaded, if he has violated the regulations, he has to take it orally.
(3) Because the advertisement image is clear and the effect is good, the number of units that advertise on the bus increases in geometric figures, and the passenger service companies have found a lot of new business opportunities.
(4) Leaders of public transport groups and passenger transport service companies often see employees'hard work from videos, and the relationship between cadres and masses has been improved unprecedentedly. Many touching deeds have become living textbooks. Individual crew members' fees for violation of regulations have become negative models, rewards and punishments are more distinct, and management effect is excellent.
Visitors will have a more pleasant journey when they see more clearly advertised entertainment programs.
(5) Criminals are deterred, and traffic accidents have decreased rapidly since then, and car crimes have declined dramatically.
Vehicle-mounted hard disk video recorder not only realizes its economic value, but also achieves unprecedented social value.