IL278777A

IL278777A - Batteries controller for drones

Info

Publication number: IL278777A
Application number: IL278777A
Authority: IL
Inventors: Parpara David
Original assignee: Hevendrones Ltd; Parpara David
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2022-06-01
Also published as: WO2022107133A1

Description

BATTERIES CONTROLLER FOR DRONES Field of the Invention The present invention relates to the field of batteries controllers. More particularly, the present invention relates to batteries controller for drones for significantly increasing the drone's flight duration.

Background of the Invention In the field of drones, the goal is to keep the drone in the air as long as possible by extending the flight duration. Usually, the flight duration of a drone using a single battery is about 30 minutes. One conventional method for extending the flight duration is connecting two batteries in parallel and feed the drone’s motor from both batteries at the same time.

However, this extends the flight duration only to about 40 minutes, i.e., by using conventional parallel connection methods, the flight duration is increased only by 10-20%.

The reason for such a small extension is that in a simple parallel connection, each battery loads the other battery, such that there are continuous charge and discharge operations.

This unwanted loading significantly reduces the effective flight duration. In addition, adding a second battery also increases the weight of the drone, which consumes additional power from the batteries, in order to lift the extra weight. Of course, there is a tradeoff between adding the weight of more batteries and the effective increase in the flight duration, but generally, adding at least one additional battery is still effective.

Another solution to prevent such loading is to switch between batteries and allow only one battery to provide power to the drone at a time. However, during the switching time, the drone’s motors receive no power and the effective elevation power is averagely reduced.

In order to increase the flight duration of the drone significantly more (for example, duplicate it to one hour instead of 30 minutes), a different connection of the drone batteries is required, a connection in which there is no disconnection in the electrical 41021/20- circuit of the batteries for even a fraction of a second. If there is a disconnection between the batteries when switching from battery to battery using the battery controller, this will prevent one of the batteries from receiving electrical power and the drone may lose its aviation power (lifting power) and fall down to the ground.

It is therefore an object of the present invention to provide a batteries controller for drones, which significantly increases the drone's flight duration upon feeding the drone’s motors from at least two batteries.

It is another object of the present invention to provide a battery controller for drones, which prevents the loading of a battery by another battery.

It is a further object of the present invention to provide a batteries controller for drones, which eliminates loss of lift power.

Other objects and advantages of the invention will become apparent as the description proceeds.

Brief Description of the Drawings The above and other characteristics and advantages of the invention will be better understood through the following illustrative and non-limitative detailed description of preferred embodiments thereof, with reference to the appended drawings, wherein: - Fig. 1 is a schematic diagram of the control circuit 100 for switching between two batteries, Bat A and Bat B, according to an embodiment of the invention; - Fig. 2 is a schematic diagram of a regulation circuit for sensing the voltage of each battery and applying the required voltage to a bi-color LED; and - Fig. 3 is a schematic diagram of a power switch, which performs the actual switching between batteries. 41021/20- Detailed Description of the Present Invention The present invention relates to a batteries control circuit for drones, for significantly increasing the drone's flight duration by using at least two batteries, while eliminating the loss of lift power. Generally, the control circuit comprises a microprocessor, which continuously monitors the voltage of each battery (typically providing a voltage of 48 V and current up to 50A) and makes an optimal decision when to switch from a battery to another battery, while allowing only one battery to feed power to the drone’s motors at a time. The control circuit comprises a redundant power source, for feeding power to the drone’s motors during the switching period, such that during the entire flight period, the drone’s motors are never disconnected from electric power, and before and after the stitching period, only one battery feeds power to the drone’s motors.

Fig. 1 is a schematic diagram of the control circuit 100 for switching between two batteries, Bat A and Bat B, according to an embodiment of the invention. Actual switching is performed by a programmable processor U2 which monitors the output voltage of each battery and makes a decision about the switching scheme according to pre-programmed rules that are burned into U2 via programming interface U1.

Bat A is connected via an integrated circuit U3 to processor U2 and Bat B is connected via an integrated circuit U4 to processor U2. J1-J3 are programming inputs of processor U2, which allows a user to determine or change the pre-programmed rules.

The control circuit 100 also comprises an energy storage and discharge sub-circuit 101, the output of which is connected to the drone’s motors via output 102. Sub-circuit 101 comprises a capacitor C1 serially connected to a rectifier diode D2, which together serve as a redundant power source for feeding power to the drone’s motors during the switching time. During the time before switching (when one of the batteries is currently connected to output 102), processor U2 controls capacitor C1 to be charged from the currently 41021/20- connected battery (Bat A or Bat B). Upon switching, processor U2 disconnects the connected battery (Bat A or Bat B) from output 102 and controls sub-circuit 101 to discharge and inject the charge of capacitor C1 into the drone’s motors via rectifier diode D2 and output 102. Capacitor C1 is sufficiently large, such that the injected charge feeds the drone’s motors until the switching process is completed and the drone’s motors are fed by the other battery. At this stage, capacitor C1 is connected to the other battery and is being recharged via resistor R3 or R7, so as to be ready for the next switching operation.

This way, the control circuit 100 assures that during each switching period, the drone’s motors are fed by the energy accumulated by sub-circuit 101.

Typically, switching between the batteries is done every 2-3 seconds. This timing is programmable and may be predetermined or changed on-demand. A typical switching period is about 0.1 mSec.

The control circuit 100 also comprises a bi-color LED D1, which provides an indication of which battery is currently connected and provides power to the drone’s motor, using a different color for each battery.

The example above refers to using two batteries. However, the invention may be implemented using a bank of batteries. For example, by using 4 batteries and switching between them, the flight period may be increased up to 55 min.

The control circuit 100 also comprises a manual switch SW1, which allows the user to intervene in the switching process and for example, allow using only one battery.

Fig. 2 is a schematic diagram of a regulation circuit for sensing the voltage of each battery and applying the required voltage to bi-color LED D1, to indicate which battery is currently used for powering the drone’s motors. 41021/20- Fig. 3 is a schematic diagram of a power switch, which performs the actual switching between batteries, such that only one battery feeds power to the drone’s motor via connector J5 (which may be, for example, an XT90 connector) at steady state. The power switch comprises two similar switching sections 300a and 300b. Switching section 300a samples the voltage of Bat A via the voltage divider of resistors R22 and R25 and provides the reading to processor U2 via output BatA_SampV, which is connected to leg 14 of processor U2. Similarly, switching section 300b samples the voltage of Bat B via the voltage divider of resistors R33 and R36 and provides the reading to processor U2 via output BatB_SampV, which is connected to leg 16 of processor U2. In turn, processor U2 sends commands to switching sections 300a and 300b (via control inputs BatA_Ctrl and BatA_Ctrl, respectively) which battery should be connected to the common output 301.

The above examples and description have of course been provided only for the purpose of illustration, and are not intended to limit the invention in any way. As will be appreciated by the skilled person, the invention can be carried out in a great variety of ways, employing more than one technique from those described above, all without exceeding the scope of the invention.

Claims

1. A batteries controller for drones for significantly increasing the drone's flight duration, comprising: a) a programmable processor (such as a microprocessor), which continuously monitors the voltage of each battery and makes multiple optimal decisions, each time, when to switch from a battery to another battery, while before and after each switching period, allowing only one battery to feed power to the drone’s motors at a time; b) a redundant power source being controlled by said programmable processor, for feeding power to the drone’s motors during said switching period, such that during the entire flight period, the drone’s motors are never disconnected from electric power; and c) a power switch, being controlled by said programmable processor, for allowing only one battery to feed power to the drone’s motors before and after each switching period.

2. A controller according to claim 1, wherein the programmable processor monitors the output voltage of each battery and makes a decision about the switching scheme according to pre-programmed rules that are burned into said programmable processor via a programming interface.

3. A controller according to claim 1, wherein the redundant power source comprises an energy storage and discharge sub-circuit that consists of a capacitor being serially connected to a rectifier diode for feeding power to the drone’s motors during the switching time. 41021/20- - 7 -

4. A controller according to claim 1, wherein the capacitor is sufficiently large, such that the injected charge feeds the drone’s motors until the switching process is completed and the drone’s motors are fed by the other battery, where while said capacitor is connected to the other battery, it is being recharged from said other battery, so as to be ready for the next switching operation.

5. A controller according to claim 1, wherein switching between the batteries is typically done every 2-3 seconds. This timing is programmable and may be predetermined or changed on-demand. A typical switching period is about 0.1 mSec.

6. A controller according to claim 1, further comprising a bi-color LED for providing an indication which battery is currently connected and provides power to the drone’s motor.

7. A controller according to claim 1, adapted to control a bank of batteries.

8. A controller according to claim 1, further comprising a manual switch, which allows the user to intervene in the switching process.

9. A controller according to claim 1, wherein the battery voltage is 48 V and the current is up to 50 A.