Hybrid unmanned aerial vehicle, and method and apparatus for managing energy thereof

Abstract

The present invention provides a hybrid unmanned aerial vehicle, and a method and an apparatus for managing energy thereof. The present invention provides an apparatus for managing energy of a hybrid unmanned aerial vehicle comprising an internal combustion engine and an electric motor. The apparatus comprises a processor and a memory connected to the processor. The memory stores program instructions which are executed by the processor such that, if the unmanned aerial vehicle navigates in an electric motor driving mode after taking off and ascending, it is determined whether the state of charge (SOC) of a battery is lower than a preset first reference value; if the SOC is lower than the first reference value, power from the internal combustion engine operates the electric motor as a generator so as to charge the battery; in the process of charging the battery, it is determined whether the temperature of the battery is lower than a preset second reference value; and if the temperature of the battery is lower than the second reference value, the battery is heated by using heat generated from the internal combustion engine.

Description

Hybrid unmanned aerial vehicle, energy management method and device therefor

[0001] The present invention relates to a hybrid unmanned aerial vehicle, an energy management method and a device therefor.

[0002] Vertical take-off and landing unmanned aerial vehicles, such as drones, have the advantage of not requiring separate take-off and landing facilities and equipment, but have the disadvantage of lower performance compared to fixed-wing aircraft of the same class in terms of high-speed flight, payload, and endurance.

[0003] This trend becomes more pronounced as the takeoff weight of UAVs decreases. Compared to fixed-wing aircraft, which can utilize a variety of propulsion systems ranging from electric motors to jet engines, vertical takeoff and landing UAVs, which rely primarily on the shaft horsepower of their engines, face limited propulsion system options as their weight decreases.

[0004] When designing small UAVs for vertical takeoff and landing (VTOL), supplying the power required for VTOL via a reciprocating engine inevitably necessitates larger aircraft. Consequently, the propulsion system weight is excessive compared to the UAV's empty weight, making it difficult to secure the payload, space, and endurance required for the mission. Typically, VTOL UAVs exhibit significant differences in power requirements during VTOL and cruise flight. In VTOL UAVs, VTOL accounts for a very small portion of the total mission time.

[0005] To address this issue, hybrid propulsion systems are being developed, combining two or more power sources with different configurations to improve overall system performance. While various types of power sources can be combined, the most common configuration is a hybrid propulsion system combining an internal combustion engine and an electric motor with a lithium-ion battery. To achieve optimal energy efficiency, the distribution of power generated by the hybrid power source, combining an internal combustion engine and an electric motor, is crucial.

[0006] Additionally, to increase the flight range, it is necessary to consider improving the SOC efficiency of lithium-ion batteries, and temperature is a factor that affects this. As the operating altitude of the drone increases, the atmospheric temperature tends to decrease. Based on 25℃, which is the temperature that can maintain the optimal performance of lithium-ion batteries, when the temperature of lithium-ion batteries is -20℃ and 45℃, the charge capacity decreases by 33% and 1.8%, respectively. Therefore, in order to maintain the optimal temperature of lithium-ion batteries, efficient thermal management must be performed to heat at low temperatures and cool at high temperatures.

[0007] In order to solve the problems of the above-mentioned prior art, the present invention proposes an energy management method and device for a hybrid unmanned aerial vehicle that can appropriately distribute output generated from a hybrid power source and also maintain a lithium-ion battery at an optimal temperature according to altitude.

[0008] In order to achieve the above object, according to one embodiment of the present invention, there is provided an energy management device for a hybrid unmanned aerial vehicle including an internal combustion engine and an electric motor, comprising: a processor; and a memory connected to the processor, wherein the memory stores program instructions executed by the processor, wherein when the unmanned aerial vehicle cruises in an electric motor drive mode after takeoff and ascent, the memory determines whether a state of charge (SOC) of a battery is lower than a first preset reference value, and when the SOC is lower than the first reference value, the power of the internal combustion engine operates the electric motor as a generator to charge the battery, and during the charging process of the battery, the temperature of the battery is determined lower than a second preset reference value, and when the temperature of the battery is lower than the second reference value, the energy management device for a hybrid unmanned aerial vehicle is heated using heat generated by the internal combustion engine.

[0009] The above internal combustion engine may be a Wankel propulsion engine.

[0010] The above program commands may cause the power of the internal combustion engine to be used to support the power of the electric motor for additional acceleration if the SOC is not lower than the first reference value.

[0011] The above program commands may monitor the altitude of the unmanned aerial vehicle and, if the monitored operating altitude is higher than a preset height, heat generated from the internal combustion engine may be used to heat the battery.

[0012] The above program commands may be configured to cause the power of the internal combustion engine to be used to support the power of the electric motor for landing when the SOC is not lower than the first reference value during descent and landing of the unmanned aerial vehicle.

[0013] According to another aspect of the present invention, a hybrid unmanned aerial vehicle is provided, comprising: an internal combustion engine that transmits power to a propeller through a transmission; an electric motor that is connected to a battery and transmits power to the propeller through the transmission; and a control unit that controls at least one of the internal combustion engine and the electric motor to transmit power to the propeller during takeoff, ascent, cruising, descent, and landing, monitors the SOC (State of Charge) of the battery so that the power of the internal combustion engine operates the electric motor as a generator to charge the battery, and monitors the temperature of the battery so that the heat generated by the internal combustion engine is used to heat the battery.

[0014] According to another aspect of the present invention, there is provided a method for managing energy of a hybrid unmanned aerial vehicle in a device including an internal combustion engine and an electric motor, the method comprising: when the unmanned aerial vehicle cruises in an electric motor driving mode after takeoff and ascent, determining whether a State of Charge (SOC) of a battery is lower than a first preset reference value; if the SOC is lower than the first reference value, charging the battery by operating the electric motor as a generator using the power of the internal combustion engine; determining whether a temperature of the battery is lower than a second preset reference value during the charging process of the battery; and if the temperature of the battery is lower than the second reference value, heating the battery using heat generated by the internal combustion engine.

[0015] According to the present invention, power transmission of a hybrid unmanned aerial vehicle including an internal combustion engine and an electric motor can be optimally distributed, and battery charging efficiency can be increased by heating the battery with the heat of the internal combustion engine as the altitude increases.

[0016] FIG. 1 is a diagram illustrating the configuration of a hybrid unmanned aerial vehicle according to the present embodiment.

[0017] Figure 2 is a flowchart for power management during the takeoff and cruising process of a hybrid unmanned aerial vehicle according to the present embodiment.

[0018] Figure 3 is a flowchart for power management during the descent and landing process of a hybrid unmanned aerial vehicle according to the present embodiment.

[0019] Fig. 4 is a diagram illustrating the configuration of an energy management device of an unmanned aerial vehicle according to the present embodiment.

[0020] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0021] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0022] In addition, it is to be understood that the components of the embodiments described with reference to each drawing are not limited to the specific embodiments, but may be implemented to be included in other embodiments within the scope in which the technical idea of ​​the present invention is maintained, and that multiple embodiments may be re-implemented as a single integrated embodiment even if a separate description is omitted.

[0023] In addition, when describing with reference to the attached drawings, identical components will be assigned identical or related reference numerals regardless of the drawing reference numbers, and redundant descriptions thereof will be omitted. When describing the present invention, if a detailed description of a related known technology is judged to unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

[0024]

[0025] This embodiment appropriately distributes and supplies power from an internal combustion engine and an electric motor to a propeller according to the required output for each operating situation of an unmanned aerial vehicle.

[0026] In particular, the present embodiment proposes a control method for a hybrid unmanned aerial vehicle that uses a Wankel propulsion system that does not reciprocate and an electric motor including a lithium-ion battery as a power source.

[0027] FIG. 1 is a diagram illustrating the configuration of a hybrid unmanned aerial vehicle according to the present embodiment.

[0028] FIG. 1 is a drawing illustrating a parallel hybrid configuration, and the hybrid unmanned aerial vehicle according to the present embodiment includes a Wankel propulsion unit (100) and an electric motor (102).

[0029] The Wankel thruster (100) and the electric motor (102) are both mechanically connected to the propeller (106) via a transmission (104) and can supply propulsion power to the unmanned aerial vehicle simultaneously or individually.

[0030] The power generated from the Wankel propulsion device (100) is used to support the power of the electric motor (102) and to charge the lithium-ion battery (108), and is transmitted to the propeller (106) and the electric motor (102) individually or simultaneously by controlling the transmission (104).

[0031] The electric motor (102) supplies power to the unmanned aerial vehicle and, depending on the operating conditions, switches to the role of a generator and operates in hybrid power generation mode.

[0032] Although not shown in FIG. 1, the hybrid unmanned aerial vehicle according to the present embodiment may additionally be equipped with a control unit that controls at least one of the internal combustion engine, the Wankel propulsion (100) and the electric motor (102), to transmit power to the propeller (106) during takeoff, ascent, cruising, descent, and landing, monitors the SOC (State of Charge) of the battery (108) so that the power of the Wankel propulsion (100) operates the electric motor (102) as a generator to charge the battery (108), and monitors the temperature (T) of the battery (108) so that the heat generated from the Wankel propulsion (100) is used to heat the battery (108).

[0033] Below, the energy management process according to the present embodiment is described in detail with reference to the drawings. Here, the energy management process can be performed by the control unit.

[0034] Figure 2 is a flowchart for power management during the takeoff and cruising process of a hybrid unmanned aerial vehicle according to the present embodiment.

[0035] Referring to Figure 2, the SOC (State of Charge) of the battery before flight is set to 100% (step 200).

[0036] SOC is the remaining capacity of the battery, expressed as a percentage (%) by dividing the currently usable battery capacity by the total capacity.

[0037] During the takeoff and ascent process, the highest power is required, so the Wankel thruster (100) and electric motor (102) operate in hybrid mode to generate maximum output (step 202).

[0038] After reaching the target altitude, the aircraft moves only with the power of the electric motor during cruising (turning, entry, exit) (step 204).

[0039] At this time, the Wankel thruster (100) operates in two modes depending on the SOC of the lithium-ion battery (108).

[0040] During cruising, it is determined whether the SOC is lower than a preset reference value (α) (step 206), and if the SOC is not lower than the reference value, the power of the Wankel propulsion unit (100) is used to support the electric motor (102) in a situation where additional acceleration, etc. is required (step 208), and if the SOC becomes lower than the reference value, the power of the Wankel propulsion unit (100) is used to operate the electric motor (102) as a generator to charge the lithium ion battery (108) (step 210).

[0041] In the process of charging a lithium-ion battery (108) with a Wankel propulsion device (100), it is determined whether the temperature of the battery (108) is lower than a reference value (β) (step 212), and if the temperature of the battery (108) is lower than the reference value, the heat generated from the Wankel propulsion device (100) is used for heating, thereby increasing the charging / discharging efficiency (step 214).

[0042] According to this embodiment, before monitoring the temperature of the battery, the altitude of the drone itself can be determined in advance, and battery heating can be performed if the current altitude is higher than a preset height.

[0043] Figure 3 is a flowchart for power management during the descent and landing process of a hybrid unmanned aerial vehicle according to the present embodiment.

[0044] Referring to FIG. 3, when entering the descent and landing phase, only the power of the electric motor (102) is used (step 300). At this time, as in FIG. 2, it is determined whether the SOC is lower than a preset reference value (α) (step 302). If the SOC is not lower than the reference value, the power of the Wankel thruster (100) is used to support the electric motor (102) in a situation where additional acceleration, etc. is required (step 304). If the SOC becomes lower than the reference value, the power of the Wankel thruster (100) is used to operate the electric motor (102) as a generator to charge the lithium ion battery (108) (step 306).

[0045] Even during descent and landing, in the process of charging the lithium ion battery (108) with the Wankel thruster (100), it is determined whether the temperature of the battery (108) is lower than the reference value (β) (step 308), and if the temperature of the battery (108) is lower than the reference value, the heat generated from the Wankel thruster (100) is used for heating, thereby increasing the charging and discharging efficiency (step 310).

[0046] The energy management method of a hybrid unmanned aerial vehicle according to the present embodiment can be performed by a computing device including a processor and a memory.

[0047] Fig. 4 is a diagram illustrating the configuration of an energy management device of an unmanned aerial vehicle according to the present embodiment.

[0048] Referring to FIG. 4, here, the processor (400) may include a central processing unit (CPU) capable of executing a computer program or a virtual machine, etc.

[0049] Memory (402) may include a non-volatile storage device such as a fixed hard drive or a removable storage device. Removable storage devices may include a compact flash unit, a USB memory stick, etc. Memory (402) may also include volatile memory such as various random access memories, and may be defined as a computer-readable recording medium.

[0050] In the memory (402) according to the present embodiment, program commands are stored that can determine one of the electric motor driving mode among the hybrid power sources, comparison of SOC with a reference value, and acceleration / landing / power generation through this, and determine whether to heat the battery by comparing the temperature of the battery with a reference value during power generation.

[0051] The above-described embodiments of the present invention are disclosed for the purpose of illustration, and those skilled in the art with common knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following patent claims.

Claims

1. An energy management device for a hybrid unmanned aerial vehicle including an internal combustion engine and an electric motor, processor; and Including a memory connected to the above processor, The above memory is, When the above drone is cruising in electric motor drive mode after takeoff and ascent, it is determined whether the SOC (State of Charge) of the battery is lower than a preset first reference value, When the above SOC is lower than the first reference value, the power of the internal combustion engine operates the electric motor as a generator to charge the battery, During the charging process of the above battery, it is determined whether the temperature of the above battery is lower than a preset second reference value, When the temperature of the battery is lower than the second reference value, the battery is heated using the heat generated from the internal combustion engine. An energy management device for a hybrid unmanned aerial vehicle storing program instructions executed by the above processor.

2. In paragraph 1, The above internal combustion engine is an energy management device for a hybrid unmanned aerial vehicle, which is a Wankel propulsion engine.

3. In paragraph 1, The above program commands are: An energy management device of a hybrid unmanned aerial vehicle, which allows the power of the internal combustion engine to be used to support the power of the electric motor for additional acceleration when the SOC is not lower than the first reference value.

4. In paragraph 1, The above program commands are: Monitor the altitude of the above drone, An energy management device of a hybrid unmanned aerial vehicle that heats the battery using heat generated from the internal combustion engine when the monitored operating altitude is higher than a preset height.

5. In paragraph 1, The above program commands are: An energy management device of a hybrid unmanned aerial vehicle, which enables the power of the internal combustion engine to be used to support the power of the electric motor for landing when the SOC is not lower than the first reference value during descent and landing of the unmanned aerial vehicle.

6. As a hybrid unmanned aerial vehicle, An internal combustion engine that transmits power to a propeller through a transmission; An electric motor connected to the battery and transmitting power to the propeller through the transmission; and A hybrid unmanned aerial vehicle comprising a control unit configured to control, during takeoff, ascent, cruising, descent and landing, at least one of the internal combustion engine and the electric motor to transmit power to the propeller, monitor the SOC (State of Charge) of the battery so that the power of the internal combustion engine operates the electric motor as a generator to charge the battery, and monitor the temperature of the battery so that the heat generated by the internal combustion engine is used to heat the battery.

7. In paragraph 6, The above internal combustion engine is a hybrid unmanned aerial vehicle with a Wankel propulsion engine.

8. In paragraph 6, A hybrid unmanned aerial vehicle, wherein the control unit determines whether the SOC (State of Charge) of the battery is lower than a first preset reference value when the unmanned aerial vehicle cruises in an electric motor-driven mode after takeoff and ascent, and, if the SOC is lower than the first reference value, causes the power of the internal combustion engine to operate the electric motor as a generator to charge the battery.

9. In paragraph 6, A hybrid unmanned aerial vehicle wherein the control unit determines, during the charging process of the battery, whether the temperature of the battery is lower than a preset second reference value, and, if the temperature of the battery is lower than the second reference value, heats the battery using heat generated from the internal combustion engine.

10. A method for managing energy of a hybrid unmanned aerial vehicle in a device including an internal combustion engine and an electric motor, A step of determining whether the SOC (State of Charge) of the battery is lower than a preset first reference value when the drone is cruising in an electric motor drive mode after takeoff and ascent; A step of charging the battery by operating the electric motor as a generator using the power of the internal combustion engine when the SOC is lower than the first reference value; During the charging process of the battery, a step of determining whether the temperature of the battery is lower than a preset second reference value; and An energy management method for a hybrid unmanned aerial vehicle, comprising a step of heating the battery using heat generated from the internal combustion engine when the temperature of the battery is lower than the second reference value.

Images