Live video streaming
Possibility
of online video broadcasting from the quadcopter to an external device — smartphone, laptop, control panel with display, virtual reality glasses, etc.
This feature provides several benefits at once. Firstly, it greatly simplifies the control of the device, even if it is within sight; and if the copter is not visible from the ground (which happens often, especially when using heavy professional equipment), then it is very difficult to do without "eyes on board". Secondly, live broadcasting makes it possible to use a drone for real-time observations, as well as full-fledged aerial photo and video shooting; recording of footage can be carried out both on an external device that receives the broadcast, and on the aircraft’s own carrier (usually a memory card — see below).
The specific features of the live broadcast for each model should be clarified separately; however, nowadays, thanks to the development of technology, such an opportunity is available even in low-cost devices.
Control
The control method provided in the copter.
Modern drones are usually controlled by a
remote control, a
smartphone, or
both. Here is a detailed description of each of these options:
— Remote control only. Management carried out exclusively from the complete remote control. The most common option, found in all varieties of drones — from the simplest entertainment models to high-end professional devices; and heavy commercial / industrial models (see "Type") are completely controlled exclusively in this way. Such popularity is explained by two points. Firstly, the functionality of the remote control can be almost anything — from a small device with a couple of levers and buttons to a multifunctional control unit with a screen for live broadcasts and displaying various specialized information. Thus, the equipment of the remote control can be optimally matched to the features of a particular copter. Secondly, you can install a powerful transmitter with a large range in the remote control (whereas the range of smartphones is very limited, and it also depends on the specific gadget model). Well, besides, the control panel is initially supplied with the drone (except that the batteries in some models need to be purchased separately).
— Smartphone only. Management carried out exclusively from a smartphone (or other similar gadget — for example, a tab
...let) through a special application; communication is usually carried out via Wi-Fi. This option is good because almost any functionality can be provided in the control application; and the copter itself turns out to be convenient in transportation — in the sense that you do not need to carry a separate remote control with it. However, the range in such a control is very small — even under perfect conditions, it usually does not exceed 100 m, and in some models it does not even reach 50 m; and the actual communication range also strongly depends on the characteristics of the control gadget. In addition, the controls on the touch screen are not tactile, making blind control almost impossible. As a result, this option is very rare — in certain models of mini-drones and selfie-drones (see "In the direction"), for which the absence of a remote control and ease of carrying are important, and the described disadvantages are not critical.
— Remote control and smartphone. The ability to control the drone both from the remote control and from a smartphone. The features of both options are described in detail above; and their combination is found mainly in relatively simple devices, for which the shortcomings of control via a smartphone are not critical (although there are exceptions). At the same time, the main option for such copters is often control from an external gadget, and the remote control may not be included at all; This point does not hurt to clarify before buying. However, anyway, this control format gives the user the opportunity to choose the best option for a specific situation. For example, for recreational flights during a "sally" in nature, you can get by with a smartphone, and for aerobatic training, a remote control is better. So most modern quadcopters that can be controlled from a smartphone / tablet fall into this category.Control frequency
The frequency used to communicate between the aircraft and its control device (usually a remote control).
Some time ago, devices with analog control at a frequency of 27.145 MHz and 40 MHz could be found on sale. However, today these standards have practically fallen out of use and modern copter drones mainly use digital communications at a frequency of
2.4 GHz or
5.8 GHz(and some models support both of these ranges at once). This type of control has a number of advantages over analogue control. Firstly, it is less sensitive to interference: on an analog channel, a drone can mistake possible interference for a command and make an unexpected maneuver, while distortion of digital data is perceived precisely as distortion and does not affect the operation of the device. Secondly, the digital format provides high bandwidth, allowing you to even broadcast high-definition video directly from a drone. Thirdly, with this control, each “remote control-copter” pair is automatically allocated its own communication channel, and the system first checks whether it is being used by another pair of devices. Thanks to this, several devices can operate in close proximity without interfering with each other.
As for the features of specific frequency ranges, they are as follows:
- 2.4 GHz. The most popular standard in modern drones. This is due, on the one hand, to low cost (with all the advan
...tages of digital control), and on the other hand, to expanded compatibility. The fact is that 2.4 GHz is the most common range of Wi-Fi modules in smartphones, tablets, etc.; so compatibility with this range allows you to easily supplement the drone with the ability to control it from an external gadget (however, this capability is not mandatory). One of the disadvantages of 2.4 GHz is also associated with the abundance of devices that use this frequency: in addition to Wi-Fi, these are Bluetooth modules, some other electronic devices, as well as most remote controls for radio-controlled equipment (not just copters). So this range is somewhat inferior to the 5.8-GHz range in terms of noise immunity; on the other hand, even with a busy broadcast, this moment is extremely rarely noticeable.
- 5.8 GHz. Further, after the 2.4 GHz described above, the development of digital standards. Allows for a longer communication range and is also more reliable, since there are significantly fewer extraneous signal sources at the 5.8 GHz frequency. In addition, the increase in frequency made it possible to increase bandwidth and effectively broadcast HD video from copters in the most advanced standards. However, some of the newest Wi-Fi standards also include support for this range, so drones in this category can also allow control from a smartphone (however, in such cases it is worth paying special attention to compatibility). The disadvantages of this option include the relatively high cost; however, thanks to the development and cheaper technology, support for 5.8 GHz can now be found even in relatively inexpensive copters.
- 2.4 GHz and 5.8 GHz. Support for both ranges described above - as a rule, with the ability to use any of them, at the user's choice. This provides additional convenience, reliability and versatility. For example, a model with two control methods (see “Control”) can use the 2.4 GHz band when working with a smartphone (which ensures a minimum of compatibility problems), and work with a remote control at 5.8 GHz (for maximum range and reliability). And drones controlled only from a remote control may even have a function such as automatically scanning ranges and selecting the least loaded one. At the same time, dual-band models are slightly more expensive than single-band ones, but the difference in price (especially with devices only at 5.8 GHz) is not particularly significant. So most modern copters capable of operating at a frequency of 5.8 GHz fall into this category.
When using specialized communication protocols, control signals between the copter and the remote control can be transmitted at special frequencies: 720 MHz, 915 (868) MHz.Remote control power source
The number and type of batteries used in the quadcopter control panel.
— AA. Replaceable batteries, colloquially known as "AA batteries". They are available not only in the form of disposable batteries, but also in the form of rechargeable batteries, are produced under various brands that differ in price and quality (which provides freedom of choice), and finding such elements on the market is usually not a problem. The power and capacity of AA elements are relatively small, but in most cases they are quite enough for normal operation of the transmitter for quite a long time. Usually, modern consoles require several of these batteries; in the most high consumption this number can reach 8.
— AAA. Also known as "pinky". In fact, a smaller version of popular AA elements (see above); has the same key features, but differs in more compact dimensions and, as a result, somewhat reduced power. This option is typical for low-cost class models, with a small range of the remote control.
— 3s. This marking does not describe the size of the battery, but its operating voltage and technology. It denotes a lithium-ion or lithium-polymer battery (see "Battery type"), assembled from three cells with a standard voltage of 3.7 V each, and thereby delivering an operating voltage of 11.1 V. The advantages of such a power supply are high power and capacity, which allows you to use the remote control for a long time without recharging. At the same time, batteries of thi...s type can vary significantly in size and weight, and not every model marked 3s will be compatible with the remote control. In addition, finding a spare battery is more difficult than a set of cells of a standard size.
— Proprietary battery. Powered by an original battery that is not related to any of the options described above. Such batteries can be much more powerful than replacement cells, making them well suited even for remotes with high power consumption. Their main advantage is the difficulty with quick replacement: the design of the remote control is at best poorly suited for this, and at worst the battery is generally non-removable. Also, finding the right replacement battery can be a major hassle.
Battery capacity
The capacity of the battery supplied with the quadcopter.
Theoretically, a larger battery can provide a longer charge time. However, keep in mind that this time also depends on the power consumption of the copter — and it is determined by the power of the engines, dimensions and weight, as well as a number of other features. In addition, the actual battery capacity is determined not only by ampere-hours, but also by its nominal voltage. Therefore, only quadcopters with the same battery voltage and similar operating characteristics can be compared by amp-hours; and it is best to evaluate battery life by directly claimed flight time (see below).
Dimensions
General dimensions of the device. A fairly obvious parameter; we only note that for models with a folding structure (see above), in this paragraph, the dimensions in the working (unfolded) position are given, and the dimensions in the folded form are specified separately.