Specialized mobile recorders have recently found increasing use in various transport sectors, government services and where a number of parameters are required that are unique to this type of equipment.
Let's note the main ones, using the example of the D-147M automobile recorder manufactured by ACUMEN.
The main thing we will focus on in the technical part of the article is: temperature conditions, the level of permissible vibrations, resistance to interference and voltage drops, as well as functionality and the level of adaptation to our Russian realities. The most vulnerable part in mobile versions of recording devices is the storage device.
Moreover, the vulnerability lies in the strategy of its selection.
For example, if we choose a recording device based on a solid-state drive (removable flash drive), we get a guarantee of operation at a wider range of temperatures and vibrations.
But here the problem of capacity and quality of the archive arises, because it is impossible to get a full-fledged long-term archive on 8 GB storage devices.
In this regard, most manufacturers act differently.
They use hard drives as storage media, but improve the vibration stabilization system and internal «climate control».
This results in a 1 TB archive with full HDD protection at critical moments.
When testing the above-mentioned D147M recorder, it was noted that it has 2-level vibration stabilization in a wide frequency range (5 Hz-500 Hz at 1.65 G), as well as protection against overloads in all planes (falls, accidents, up to 8 G!).
The heating module is located directly in the box under the HDD, which directly affects the stability of temperature maintenance and reduces the time it takes to bring the device into working condition at low temperatures.
The developers paid special attention to the protection unit and power supply circuits in this model: it seems that the designers initially took into account the option of connecting the recorder to a Zhiguli or KAMAZ. The input voltage of the Ai-D147M recorder is 12-24 V!
Moreover, the stabilization unit is not based on the generally accepted linear scheme, but on the basis of a PWM (pulse) converter.
I will cite one of the advantages of this technical solution: no matter what happens in the power supply circuit, the supply voltage of the recorder will never be higher than it should be!
This happens because, unlike a linear stabilizer, the very principle of pulse conversion excludes this variant of events.
Therefore, the recorder is fully equipped with protection against the main problem areas, including video inputs.
A big advantage of the recorder's case design is the use of a standard 1Din design. This means that the D147M recorder can be installed in any car and in public transport in a matter of minutes.
At the same time, the entire front panel with the control keyboard is accessible, as in the case of a conventional radio. The developers paid special attention to the presence of a locking key, a network connector, a USB output for connecting a mouse (or a removable disk), and a connector for an SD memory card in the front panel.
The recorder can be connected via VGA to any LCD receiver (any, because in the recorder menu we can change the desktop resolution).
To control the menu, archive, recording functions and other options, we use the control keys, IR remote control or the «TrackBall» manipulator.
Viewing can be done both from the device itself and from an external storage device. It is possible to physically remove the recorder from the sleds for using it later as an independent device with a 5V power supply.
It is possible to view real time on a mobile phone via the Internet. When using a GPRS modem, this access can be organized from any point on the route.
Another option: installing this configuration in public transport will allow the dispatcher to receive full real time information about what is happening both inside and outside the route vehicle.
As practice shows, the use of remote access dramatically increases the responsibility of drivers, conductors, and other participants in the transportation process, invariably with a positive result.
A separate parameter I would like to highlight is the progressive compression algorithm H-264, which is used in Ai-D147M.
Today, this is a minimal archive with maximum image quality. And in terms of high resolution and careful elaboration of small details, the H-264 codec is unrivaled by other compression algorithms.
The presence of relay inputs/outputs expands the control system of external devices in the event of an alarm or accident (the recorder has an acceleration/overload sensor, which is configured through the menu).
In addition, the advantages of the Ai-D147M car recorder include the following options:
° Free, multifunctional software included in the kit;
° 4 video channels;
° PTZ device control via RS-485 from the recorder menu;
° 2 audio inputs synchronized with video;
° Possibility of connecting GPS equipment.
The combination of all these parameters guarantees almost any desired configuration of a mobile video system.
Moreover, the extended menu and many additional functions open up prospects for this model to be used as a stationary video surveillance system! And the increased performance characteristics suggest operation in difficult conditions (factories, enterprises, construction).
In the next section of this article, we will provide several examples of using mobile recorders in existing projects.
The main direction is motor transport!
Any: city, public, service-state. Many public transport companies face problems with drivers following the route, conductors performing their duties conscientiously, and passengers observing ethical and legal standards.
All this is impossible to control, which leads to a significant decrease in the efficiency of the transport fleet.
We are no longer taking into account such extreme cases as road accidents or vandalism. Nevertheless, the installation of recording equipment with several video cameras on board pays for itself after six months of use.
Another advantage of mobile recorders is that no additional costs are required after installing the system.
And as already mentioned above, a six-month archive on the storage device gives maximum freedom of action in certain situations.
From a technical point of view, a common option is to install 2 cameras inside the cabin, one in front in the direction of the route, and an additional camera along the side of the boarding and disembarking of passengers. (Unfortunately, sometimes there are cases of passenger injuries during boarding and disembarking.)
And the video archive will provide an invaluable service in finding careless actions of the driver or carelessness of passengers.
Even the banal catching of «hares» with a subsequent fine takes on a completely different meaning when using video evidence.
Installing mobile video surveillance on special transport (for example, on police cars or emergency vehicles) reduces response time and improves the quality of services provided to taxpayers.
Again, returning to savings, installing video systems significantly reduces fuel consumption and increases the efficiency of working time.
Recently, video surveillance systems have been installed by private organizations with a large fleet of vehicles: this includes logistics of goods, taxis, and even driving training centers.
In the case of an instructor, where the level of risk of an accident also depends on the student, mobile video surveillance is the only way to understand the situation, because a road user, represented by a student, is not one without a license.
In conclusion of this article, I will give examples of using mobile video surveillance at stationary sites where equipment requirements are increased.
These can be assembly lines of an enterprise, factory workshops with a high level of interference and vibration sources, dusty material handling rooms, the process of monitoring construction sites, and much more.
In such tense conditions, conventional recorder models with minimum permissible parameters simply fail.
Here, the level of functionality and software of the Ai-D147M mobile recorder even surpasses stationary models of this class.