JP7594391B2 - Multicopter - Google Patents

Description

The present disclosure relates to a multicopter, which is a rotorcraft that flies by obtaining the necessary lift through rotors, and in particular to a multicopter having a hybrid system composed of an engine, a generator, and a battery.

As a technology relating to a multicopters having a hybrid system, Patent Document 1 discloses an unmanned aerial vehicle having an engine, a generator connected to the engine, and a battery for storing the electricity generated by the generator.

Special table 2019-501057 publication Special table 2019-502237 publication

When a battery is used below a certain temperature, it does not perform satisfactorily, whereas when it is used above a certain temperature, it performs satisfactorily but is prone to degradation and may shorten its lifespan. Therefore, it is desirable to appropriately control the temperature of the battery to improve the performance of the battery while preventing degradation. Here, Patent Document 1 does not disclose anything about temperature control of the battery. Moreover, Patent Document 2 only discloses temperature control of the battery using a heating member, and does not disclose temperature control of the battery in a multicopter (unmanned aircraft) having a hybrid system.

Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a multicopter having a hybrid system that can achieve both improved battery performance and prevention of deterioration.

One form of the present disclosure made to solve the above problems is a multicopter having a hybrid system composed of an engine, a generator that generates electricity using the engine as a power source, and a battery that can be charged with the electricity generated by the generator. The multicopter has a battery temperature measurement unit that measures the temperature of the battery, a battery temperature control unit that controls the temperature of the battery based on the temperature of the battery measured by the battery temperature measurement unit, a charge/discharge control unit that performs charge/discharge control to charge or discharge the battery, and a heating unit that heats the battery. The battery temperature control unit heats the battery using the heating unit if the temperature of the battery measured by the battery temperature measurement unit is less than a predetermined temperature after a predetermined time has elapsed after the charge/discharge control unit starts to execute the charge/discharge control, and the predetermined time becomes shorter as the current value flowing through the battery becomes larger .

According to this aspect, by actively controlling the charging and discharging of the battery while measuring the battery temperature, the battery temperature can be maintained at an appropriate temperature, thereby achieving both improved battery performance and prevention of deterioration.
In addition, when the battery temperature cannot be raised to a predetermined temperature or higher by only controlling the charge and discharge using the charge and discharge control unit, the battery temperature can be raised to the predetermined temperature or higher by also heating the battery using the heating unit. This makes it possible to more reliably improve the performance of the battery while preventing deterioration.
On the other hand, if the temperature of the battery can be kept at a predetermined temperature simply by performing charge/discharge control using the charge/discharge control unit, the frequency of operation of the heating unit can be reduced by giving priority to only the charge/discharge control, thereby reducing the power consumption of the multicopter.

In the above aspect, the battery includes a remaining charge measuring unit that measures the remaining charge of the battery, and an altitude measuring unit that measures the altitude of the multicopter , and the battery temperature control unit calculates a target battery temperature based on the remaining charge measured by the remaining charge measuring unit and the altitude measured by the altitude measuring unit, and when the temperature of the battery measured by the battery temperature measuring unit is lower than the target battery temperature, the charge and discharge control unit performs the charge and discharge control, and/or the heating unit heats the battery, and the target battery temperature is calculated using a map that specifies the relationship between the remaining charge, the altitude, and the target battery temperature, and the map specifies that the target battery temperature is higher as the remaining charge is smaller and the altitude is higher .

According to this aspect, when the temperature of the battery is lower than the target battery temperature calculated based on the remaining charge and the altitude of the multicopter , the charge/discharge control is performed and/or the heating unit is operated to raise the temperature of the battery to or above the target battery temperature. Therefore, for example, the lower the remaining charge and the higher the altitude of the multicopter , the higher the target battery temperature is set to raise the temperature of the battery to or above the target battery temperature, thereby improving the performance of the battery and increasing the amount of power that the battery can discharge. Therefore, when the remaining charge is low and the altitude of the multicopter is high, even if the engine stops and power generation by the generator stops, the multicopter can make an emergency landing using only the power discharged by the battery.

In the above aspect, it is preferable that the battery temperature control unit has an altitude measurement unit that measures the altitude of the multicopter and a parachute, and when the altitude measured by the altitude measurement unit is less than a parachute opening altitude at which the parachute in a closed state can be opened to descend the multicopter , the battery temperature control unit performs the charge and discharge control using the charge and discharge control unit and/or heats the battery using the heating unit .

According to this aspect, when the altitude of the multicopter is below the parachute opening altitude during flight, the battery temperature is increased by performing charge/discharge control and/or activating the heating unit, thereby improving the performance of the battery in advance. Therefore, even if the multicopter flies at an altitude below the parachute opening altitude and the engine is stopped with a low remaining charge, the body of the multicopter can be raised to an altitude equal to or higher than the parachute opening altitude using only the power discharged from the battery, and the parachute can be opened to land the multicopter .

In the above aspect, the vehicle includes a charge remaining amount measuring unit that measures the remaining amount of charge of the battery, an altitude measuring unit that measures the altitude of the multicopter , a fuel remaining amount measuring unit that measures the remaining amount of fuel used to drive the engine, and a position acquiring unit that acquires the position of the multicopter . The battery temperature control unit calculates a possible flight distance based on the remaining amount of charge measured by the charge remaining amount measuring unit, the altitude measured by the altitude measuring unit, and the remaining amount of fuel measured by the fuel remaining amount measuring unit, compares the calculated possible flight distance with a target flight distance, which is the distance from the position of the multicopter acquired by the position acquiring unit to the destination, and if the possible flight distance is less than the target flight distance, performs the charge and discharge control by the charge and discharge control unit , and/or heats the battery by the heating unit . This is preferable.

According to this aspect, when the flight distance of the multicopter falls short of the target flight distance, charge/discharge control is performed and/or the heating unit is operated to raise the battery temperature and improve the battery performance, i.e., to increase the battery capacity. Therefore, even if there is no time to fly the multicopter to the destination due to an emergency, for example, the flight distance can be extended and the multicopter can reach the destination by raising the battery temperature and increasing the battery capacity.

According to the multicopter disclosed herein, in a multicopter having a hybrid system, it is possible to achieve both improved battery performance and prevention of deterioration.

FIG. 2 is a side view of the multicopter of the present embodiment. FIG. 2 is a block diagram showing the configuration of the multicopter of FIG. 1 . FIG. 4 is a diagram showing the relationship between battery temperature and internal resistance. FIG. 1 is a diagram showing the relationship between the battery temperature, the number of cycles (the number of charge/discharge cycles), and the battery capacity. FIG. 11 is a flowchart showing the contents of the control performed in the 1-1 embodiment. FIG. 11 is a flowchart showing the contents of the control performed in the first and second embodiments. FIG. 11 is a flowchart showing the contents of control performed in the second embodiment. FIG. 4 is a diagram showing a map defining the relationship between the remaining charge, altitude, and target battery temperature. FIG. 13 is a flowchart showing the contents of control performed in the third embodiment. FIG. 13 is a flowchart showing the contents of control performed in the fourth embodiment. FIG. 4 is a diagram showing a map defining the relationship between the remaining charge, flight margin rate, and target battery temperature.

Hereinafter, a multicopter 1, which is an example of an embodiment of a multicopter according to the present disclosure, will be described. The multicopter 1 is a rotorcraft that flies by obtaining necessary lift from rotors, and is a rotorcraft equipped with multiple rotors. Note that the multicopter also includes an unmanned aerial vehicle (drone) capable of autonomous flight.

<Overview of Multicopter>
First, an overview of the entire multicopter 1 of this embodiment will be described.

(Multicopter configuration)
As shown in FIG. 1 , the multicopter 1 of this embodiment has an airframe 11 and an engine generator unit 12 .

The aircraft 11 is equipped with a propeller 21, a motor 22, an aircraft main body 23, and an arm 24.

There are multiple propellers 21. The multicopter 1 flies by rotating these multiple propellers 21. The number of propellers 21 may be any even number equal to or greater than four.

A plurality of motors 22 (i.e., motors for driving the propellers) are provided for each of the propellers 21, and rotate each of the propellers 21. The motors 22 are connected to the aircraft body 23 by an arm 24. As shown in FIG. 2, the motors 22 are electrically connected to the battery 31 provided in the aircraft body 23 and the generator 42 provided in the engine generator unit 12 via an ESC 36 (electric speed controller) (inverter (not shown)) and a power control unit 35 provided in the aircraft body 23. As a result, the power generated by the generator 42 and the power discharged from the battery 31 are supplied to the motors 22 via the power control unit 35 and the ESC 36.

As shown in FIG. 2, the aircraft body 23 is provided with a battery 31, a fuel tank 32, a control unit 33, a flight controller 34, a power control unit 35, an ESC 36, and the like.

The battery 31 is a charge/discharge unit (secondary battery, storage battery) that can charge and discharge power. As shown in FIG. 2, the battery 31 is electrically connected to the generator 42 via the power control unit 35, and charges the battery 31 with power generated by the generator 42. The battery 31 is also electrically connected to the motor 22 via the power control unit 35 and the ESC 36, and discharges the power to be supplied to the motor 22.

The fuel tank 32 stores fuel (e.g., gasoline) used to drive the engine 41 provided in the engine generator unit 12.

The control unit 33 is configured as a small computer and controls the entire multicopter 1. For example, the control unit 33 controls the driving of the engine 41 and controls the power generation by the generator 42.

In this embodiment, the control unit 33 is provided with a battery temperature control unit 33a and a charge/discharge control unit 33b. The battery temperature control unit 33a controls the battery temperature tbattery based on the battery temperature tbattery (i.e., the temperature of the battery 31) measured by a battery temperature measurement unit 61 described later. The charge/discharge control unit 33b performs charge/discharge control to charge or discharge the battery 31. Note that the battery temperature control unit 33a and the charge/discharge control unit 33b may be provided separately from the control unit 33.

The flight controller 34 is a device that controls the flight of the multicopter 1. This flight controller 34 sends thrust command signals to the control unit 33 and the ESC 36, while also receiving signals related to information on the state of charge (remaining charge) from the control unit 33. The flight controller 34 also receives signals of operational commands from the pilot from the controller 51, which will be described later.

The power control unit 35 is a device that controls the power supplied to the motor 22. This power control unit 35 receives power generated by the generator 42, supplies and receives power to and from the battery 31, and supplies power to the ESC 36. The power control unit 35 also receives a signal from the control unit 33 instructing it to switch between charging and discharging.

The ESC 36 is a device that controls the rotation speed of the motor 22. The ESC 36 supplies the power supplied from the power control unit 35 to the motor 22 as drive power. The ESC 36 also receives a thrust command signal from the flight controller 34.

As shown in Figures 1 and 2, the engine generator unit 12 includes an engine 41 and an electric generator 42 (i.e., a generator).

The engine 41 is the power source for the generator 42, and is, for example, a small diesel engine or a reciprocating engine. That is, the engine 41 drives the generator 42 to generate electricity to be supplied to the motor 22 or the battery 31. The engine 41 also receives a signal from the control unit 33 instructing the generator 42 to generate electric power.

The multicopter 1 also has a controller 51, as shown in FIG. 2. The controller 51 is an operation unit held by the pilot of the multicopter 1, and is, for example, a joystick.

As shown in Figures 1 and 2, the multicopter 1 of this embodiment also has a battery temperature measurement unit 61, a heat generating coating 62, a charge level measurement unit 63, an altitude measurement unit 64, a parachute 65, a fuel level measurement unit 66, and a position acquisition unit 67.

The battery temperature measuring unit 61 is a device (i.e., a temperature sensor) that measures the battery temperature tbattery. The heat generating coating 62 is a heating unit that heats the battery 31, and is a dry coating in which various conductive pigments are mixed and dispersed in a special binder. By supplying power to the coating via electrodes, it is possible to heat the entire coating.

The remaining charge measuring unit 63 is a device that measures the remaining charge SOC of the battery 31 (i.e., the amount of charge remaining in the battery 31). The altitude measuring unit 64 is a device that measures the altitude altm of the multicopter 1. The parachute 65 is normally stored in a closed state in a storage unit not shown, and is opened in the event of an emergency landing as shown by the dashed line in FIG. 1.

The fuel level measuring unit 66 is a device that measures the amount of fuel remaining in the fuel tank 32 that is used to drive the engine 41 and generate electricity with the generator 42. The position acquisition unit 67 is a device (e.g., a GPS device) that acquires the horizontal position (direction perpendicular to the height direction) of the multicopter 1.

The multicopter 1 of this embodiment also has a hybrid system including a generator 42 and a battery 31. More specifically, the hybrid system is configured as a series hybrid system including the motor 22, the battery 31, the engine 41, and the generator 42. That is, in the multicopter 1, the engine 41 is used only for generating electricity with the generator 42, the motor 22 is used to drive the propeller 21, and a system is configured with the battery 31 for recovering electricity. In this way, the multicopter 1 flies by generating electricity with the generator 42 driven by the engine 41, and driving the propeller 21 with the generated electricity. In addition, the multicopter 1 temporarily stores surplus electricity generated by the generator 42 driven by the engine 41 in the battery 31, and uses it to drive the motor 22 as needed.

(Multicopter action)
The multicopter 1 having such a configuration flies by supplying power to the motor 22 and rotating the multiple propellers 21. By controlling the rotation speed of the propellers 21 and balancing the lift obtained by the rotation of the propellers 21 with the gravity of the multicopter 1 itself, the multicopter 1 can realize hovering flight, forward, backward, and left and right movement flight. In addition, the lift generated by the propellers 21 can be increased to realize the upward flight of the multicopter 1, and the lift generated by the propellers 21 can be decreased to realize the downward flight of the multicopter 1. In addition, by controlling the rotation speed of each propeller 21 and causing an imbalance in the lift generated by the rotation of the multiple propellers 21, the multicopter 1 can realize forward, backward, and left and right movement flight. By providing a difference in the rotation speed of the propellers 21 that rotate relative to each other, a turning (rotational) flight can be realized. In addition, as a braking behavior, the multicopter 1 can be stopped by performing a reverse tilt operation in which the aircraft 11 tilts in the opposite direction to the direction in which the aircraft 11 tilts when the multicopter 1 is moving (forward, backward, or left and right flight).

<Explanation of battery temperature control>
Next, the battery temperature control for controlling the battery temperature tbattery will be described.

As shown in FIG. 3, the internal resistance of the battery 31 decreases as the battery temperature tbattery increases. Therefore, the performance of the battery 31, i.e., the battery capacity, improves as the battery temperature tbattery increases. Note that the battery capacity is the so-called discharge capacity, which is the amount of power that can be discharged (or charged) under specified conditions.

On the other hand, as shown in FIG. 4, when the battery temperature tbattery is high, the battery capacity is high, but the battery 31 is more susceptible to deterioration, so when the battery is frequently charged and discharged and the number of charge/discharge cycles increases, the battery capacity decreases and the life of the battery 31 may be shortened.

Therefore, it is desirable to control the battery temperature tbattery to an appropriate temperature to improve the performance of the battery 31 while preventing deterioration.

Here, we will explain the battery temperature control (i.e., control of the battery temperature tbattery) performed in this embodiment.

[Example 1-1]
First, Example 1-1 will be described.

(Explanation of the contents of control)
In this embodiment, the battery temperature control is performed by monitoring the battery temperature tbattery and controlling the battery temperature tbattery so that it does not fall below an allowable temperature. When controlling the battery temperature tbattery, first, priority is given to increasing the battery temperature tbattery by performing charge/discharge control, and any insufficient increase in the battery temperature tbattery is compensated for by heating the battery 31 with the heat generating coating 62. Specifically, the battery temperature control unit 33a performs the control shown in FIG. 5.

As shown in FIG. 5, the battery temperature control unit 33a determines whether flight control is in progress, i.e., whether the multicopter 1 is flying (step S1).

If the battery temperature control unit 33a determines that flight control is in progress (step S1: YES), it retrieves the battery temperature tbattery measured by the battery temperature measurement unit 61 (step S2) and determines whether the value of the heat generation flag is "0" (step S3).

The value of the heat generation flag is set to "0" when heating of the battery 31 by the heat generation coating 62 has stopped, and is set to "1" when heating of the battery 31 by the heat generation coating 62 is being performed.

Then, if the value of the heat generation flag is "0" (step S3: YES), i.e., if heating of the battery 31 by the heat generating coating 62 has stopped, the battery temperature control unit 33a determines whether the battery temperature tbattery is less than a predetermined temperature TA (e.g., 25°C) (step S4).

Here, the predetermined temperature TA is the lower limit of an appropriate temperature range that can provide satisfactory performance of the battery 31 that can contribute to stable flight of the multicopter 1.

If the battery temperature control unit 33a determines that the battery temperature tbattery is less than the predetermined temperature TA (step S4: YES), it determines whether the value of the charge/discharge priority flag is "0" (step S5).

The value of the charge/discharge priority flag is set to "0" when charge/discharge control by the charge/discharge control unit 33b (hereinafter simply referred to as "charge/discharge control") is not given priority over heating of the battery 31 by the heat-generating coating 62, and is set to "1" when charge/discharge control is given priority over heating of the battery 31 by the heat-generating coating 62.

If the value of the charge/discharge priority flag is "0" (step S5: YES), the battery temperature control unit 33a makes a priority request to the PCU (i.e., the control unit 33) to fly using charge/discharge control (fly the multicopter 1 while executing charge/discharge control) (step S6), and determines whether or not to execute charge/discharge control in priority over heating the battery 31 by the heat-generating coating 62 (step S7).

Then, if the battery temperature control unit 33a determines that it is possible (approved) to give priority to charge/discharge control (step S7: YES), it gives priority to charge/discharge control (step S8).

In this manner, in this embodiment, when the battery temperature tbattery is below the predetermined temperature TA, the battery temperature control unit 33a controls the battery temperature tbattery by performing charge/discharge control using the charge/discharge control unit 33b to increase the battery temperature tbattery in order to obtain satisfactory performance for the battery 31.

After that, when a predetermined time A has elapsed since the start of charge/discharge control (step S9: YES), the battery temperature control unit 33a sets the value of the charge/discharge priority flag to "1" (step S10) and ends the process. Note that the greater the current value flowing through the battery 31, the shorter the predetermined time A (because the greater the current, the greater the amount of heat generated). Alternatively, instead of processing step S9, the battery temperature control unit 33a may measure the change ΔT in the battery temperature tbattery, and when the measured change ΔT in the battery temperature tbattery becomes smaller than a predetermined threshold, the battery temperature control unit 33a may proceed to processing step S10.

On the other hand, if the battery temperature control unit 33a determines in step S7 that it is not possible (not permitted) to prioritize charge/discharge control (step S7: NO), it heats the battery 31 using the heat generating coating 62 (step S11), i.e., it controls the operation of the heat generating coating 62 to control the battery temperature tbattery. Next, the battery temperature control unit 33a sets the value of the heat generation flag to "1" (step S12).

In addition, if the battery temperature control unit 33a determines in step S4 that the battery temperature tbattery is less than the predetermined temperature TA (step S4: YES), and if the battery temperature control unit 33a determines in step S5 that the value of the charge/discharge priority flag is set to "1" (step S5: NO), it heats the battery 31 using the heat-generating coating 62 while performing charge/discharge control (step S11), and sets the value of the heat-generating flag to "1" (step S12).

In this manner, in this embodiment, when the battery temperature tbattery measured by the battery temperature measurement unit 61 is below the predetermined temperature TA while the charge/discharge control unit 33b is performing charge/discharge control, the battery temperature control unit 33a activates the heat generating coating 62. As a result, while prioritizing the increase in the battery temperature tbattery through charge/discharge control, the heat generating coating 62 compensates for the insufficient increase in the battery temperature tbattery by heating the battery 31.

In addition, if the battery temperature control unit 33a determines in step S4 that the battery temperature tbattery is equal to or higher than the predetermined temperature TA (step S4: NO), it is assumed that the performance of the battery 31 is satisfactory, and normal flight control of the multicopter 1 is performed by the control unit 33 (step S13).

If the battery temperature control unit 33a determines in step S3 that the value of the heat generation flag is "1" (step S3: NO), that is, if it determines that the battery 31 is being heated by the heat generating coating 62, it determines whether the battery temperature tbattery is equal to or higher than a predetermined temperature TB (step S14). The predetermined temperature TB is a temperature higher than the predetermined temperature TA, for example, 30°C.

If the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than the predetermined temperature TB (step S14: YES), it stops heating the battery 31 by the heat generating coating 62 (step S15), i.e., it controls the battery temperature tbattery by controlling the stopping of the heat generating coating 62. Next, the battery temperature control unit 33a sets the value of the heat generation flag to "0" (step S16).

In this way, the battery temperature tbattery is prevented from becoming too high, thereby preventing deterioration of the battery 31.

Next, the battery temperature control unit 33a cancels the priority request to the PCU for flight under charge/discharge control (step S17) and sets the value of the charge/discharge priority flag to "0" (step S18). Then, the control unit 33 performs normal flight control of the multicopter 1 (step S13).

On the other hand, if the battery temperature control unit 33a determines in step S14 that the battery temperature tbattery is less than the predetermined temperature TB (step S14: NO), it ends the process.

In addition, if the battery temperature control unit 33a determines in step S1 that flight control is not in progress (step S1: NO), the control unit 33 performs ground control of the multicopter 1 (control performed when the multicopter 1 is not flying and has landed) (step S15).

(Effects of this embodiment)
According to this embodiment, the battery temperature control unit 33 a controls the battery temperature tbattery based on the battery temperature tbattery measured by the battery temperature measurement unit 61 .

In this way, by controlling the battery temperature tbattery while measuring it, the battery temperature tbattery can be kept at an appropriate temperature, thereby improving the performance of the battery 31 while preventing deterioration.

The battery temperature control unit 33a also controls the battery temperature tbattery by performing charge/discharge control to charge or discharge the battery 31.

In this way, by charging and discharging the battery 31, the battery temperature tbattery can be maintained at an appropriate temperature. This makes it possible to more reliably improve the performance of the battery 31 while preventing deterioration.

The battery temperature control unit 33a also controls the battery temperature tbattery by controlling the activation and deactivation of the heating coating 62.

In this way, the battery temperature tbattery can be maintained at an appropriate temperature by activating the heating coating 62 to heat the battery 31, or by stopping the heating coating 62 to stop heating the battery 31. This makes it possible to more reliably improve the performance of the battery 31 while preventing deterioration.

In addition, when the charge/discharge control unit 33b is performing charge/discharge control, if the battery temperature tbattery measured by the battery temperature measurement unit 61 is less than a predetermined temperature TA, the battery temperature control unit 33a activates the heat generating coating 62 to heat the battery 31.

In this way, if the battery temperature tbattery cannot be raised to the predetermined temperature TA or higher by simply performing charge/discharge control using the charge/discharge control unit 33b, the battery 31 can also be heated by the heat-generating coating 62 to raise the battery temperature tbattery to the predetermined temperature TA or higher.

On the other hand, if the battery temperature tbattery can be raised to a predetermined temperature TA or higher simply by performing charge/discharge control using the charge/discharge control unit 33b, the frequency of operation of the heating coating 62 can be reduced by prioritizing only the charge/discharge control. This allows the power consumption of the multicopter 1 to be reduced.

[Example 1-2]
Next, a first embodiment will be described.

(Explanation of the contents of control)
In this embodiment, when control is performed to increase the battery temperature tbattery, the battery 31 is heated by performing charge/discharge control by the charge/discharge control unit 33b and/or by activating the heat generating coating 62. Specifically, the battery temperature control unit 33a performs the control shown in FIG.

As shown in FIG. 6, the battery temperature control unit 33a receives the battery temperature tbattery (step S101) and determines whether the value of the heating flag is "0" (step S102).

The value of the heating flag is set to "0" when heating of the battery 31 is stopped, and is set to "1" when heating of the battery 31 is being performed.

Then, if the value of the heating flag is "0" (step S102: YES), i.e., if heating of the battery 31 has been stopped, the battery temperature control unit 33a determines whether the battery temperature tbattery is less than a predetermined temperature TA (e.g., 25°C) (step S103).

If the battery temperature control unit 33a determines that the battery temperature tbattery is lower than the predetermined temperature TA (step S103: YES), it performs charging/discharging control (or/and heating coating 62) to heat the battery 31 (step S104), sets the value of the heating flag to "1" (step S105), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S103 that the battery temperature tbattery is equal to or higher than the predetermined temperature TA (step S103: NO), it ends the process.

In addition, in step S102, if the value of the heating flag is "1" (step S102: NO), i.e., if heating of the battery 31 is being performed, the battery temperature control unit 33a determines whether the battery temperature tbattery is equal to or higher than a predetermined temperature TB (e.g., 30°C) (step S106).

If the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than the predetermined temperature TB (step S106: YES), it stops heating the battery 31 through charge/discharge control (or/and the heating coating 62) (step S107), sets the value of the heating flag to "0" (step S108), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S106 that the battery temperature tbattery is less than the predetermined temperature TB (step S106: NO), it ends the process.

(Effects of this embodiment)
According to this embodiment, in addition to the effects described in the above embodiment, the following effects are further achieved.

According to this embodiment, the battery temperature control unit 33a may control the battery temperature tbattery by only performing charge/discharge control by the charge/discharge control unit 33b, without controlling the activation and deactivation of the heat generating coating 62.

In this way, the power consumption of the multicopter 1 can be reduced by not controlling the activation and deactivation of the heating coating 62.

The battery temperature control unit 33a may also control the battery temperature tbattery by only controlling the activation and deactivation of the heat generating coating 62, without performing charge and discharge control by the charge and discharge control unit 33b.

In this way, by not performing charge/discharge control by the charge/discharge control unit 33b, the battery temperature tbattery can be increased more reliably and instantly compared to charge/discharge control.

Furthermore, the battery temperature control unit 33a may control the battery temperature tbattery by controlling the operation and stopping of the heat generating coating 62 while controlling the charge and discharge by the charge and discharge control unit 33b.

This allows the battery temperature tbattery to be controlled efficiently.

[Second embodiment]
Next, a second embodiment will be described.

(Explanation of the contents of control)
In this embodiment, the battery temperature control is performed by controlling the battery temperature tbattery according to the remaining charge SOC and the altitude altm, and in the unlikely event that the engine 41 stops, the multicopter 1 is landed using only the power of the battery 31. Specifically, the battery temperature control unit 33a performs the control shown in FIG.

As shown in FIG. 7, the battery temperature control unit 33a receives the remaining charge SOC measured by the remaining charge measurement unit 63 and the altitude altm measured by the altitude measurement unit 64 (step S201), and receives the battery temperature tbattery measured by the battery temperature measurement unit 61 (step S202).

Next, the battery temperature control unit 33a calculates the target battery temperature ktbattery according to the remaining charge SOC and the altitude altm (step S203).

Here, the target battery temperature ktbattery is calculated using the map in FIG. 8. In FIG. 8, the temperatures are highest in the order of temperature T4, temperature T3, temperature T2, and temperature T1 (temperature T1<temperature T2<temperature T3<temperature T4).

In this way, in this embodiment, the battery temperature control unit 33a calculates the target battery temperature ktbattery based on the remaining charge SOC measured by the remaining charge measurement unit 63 and the altitude altm measured by the altitude measurement unit 64.

Returning to the explanation of FIG. 7, the battery temperature control unit 33a then determines whether the value of the heating flag is "0" (step S204).

Then, if the value of the heating flag is "0" (step S204: YES), i.e., if heating of the battery 31 has been stopped, the battery temperature control unit 33a determines whether the battery temperature tbattery is less than the target battery temperature ktbattery (step S205).

If the battery temperature control unit 33a determines that the battery temperature tbattery is lower than the target battery temperature ktbattery (step S205: YES), it performs charging/discharging control (or/and heating coating 62) to heat the battery 31 (step S206), sets the value of the heating flag to "1" (step S207), and ends the process.

In this manner, in this embodiment, the battery temperature control unit 33a performs charge/discharge control and/or activates the heating coating 62 when the battery temperature tbattery measured by the battery temperature measurement unit 61 is less than the target battery temperature ktbattery calculated based on the remaining charge SOC and the altitude altm.

On the other hand, if the battery temperature control unit 33a determines in step S205 that the battery temperature tbattery is equal to or higher than the target battery temperature ktbattery (step S205: NO), it ends the process.

In addition, in step S204, if the value of the heating flag is "1" (step S204: NO), i.e., if heating of the battery 31 is being performed, the battery temperature control unit 33a determines whether the battery temperature tbattery is equal to or higher than (target battery temperature ktbattery + temperature α) (step S208).

If the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than (target battery temperature ktbattery + temperature α) (step S208: YES), it stops heating the battery 31 through charge/discharge control (or/and the heating coating 62) (step S209), sets the value of the heating flag to "0" (step S210), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S208 that the battery temperature tbattery is less than the target battery temperature ktbattery + temperature α (step S208: NO), it ends the process.

(Effects of this embodiment)
According to this embodiment, in addition to the effects described in the above embodiment, the following effects are further achieved.

According to this embodiment, the battery temperature control unit 33a calculates the target battery temperature ktbattery based on the remaining charge SOC measured by the remaining charge measurement unit 63 and the altitude altm measured by the altitude measurement unit 64. Then, when the battery temperature tbattery is lower than the target battery temperature ktbattery, the battery temperature control unit 33a performs charge/discharge control and/or activates the heating coating 62.

In this way, when the battery temperature tbattery is lower than the target battery temperature ktbattery calculated based on the remaining charge SOC and the altitude altm, the charge/discharge control is performed and/or the heating coating 62 is activated, thereby raising the battery temperature tbattery to the target battery temperature ktbattery or higher. Therefore, for example, the lower the remaining charge SOC and the higher the altitude altm, the higher the target battery temperature ktbattery is set to raise the battery temperature tbattery to the target battery temperature ktbattery or higher, thereby improving the performance of the battery 31 and increasing the amount of power that the battery 31 can discharge. Therefore, when the remaining charge SOC is low and the altitude altm is high, even if the engine 41 stops and power generation by the generator 42 stops, the multicopter 1 can be made to make an emergency landing using only the power discharged by the battery 31.

[Third Example]
Next, a third embodiment will be described.

(Explanation of the contents of control)
In this embodiment, as the battery temperature control, when the multicopter 1 is flying at an altitude below the parachute opening altitude, the battery temperature tbattery is controlled to a temperature that improves the performance of the battery 31, and in the unlikely event that the engine 41 stops, the multicopter 1 is raised to an altitude equal to or higher than the parachute opening altitude using only the power of the battery 31, and the parachute 65 is opened to land the multicopter. Specifically, the battery temperature control unit 33a performs the control shown in FIG.

As shown in FIG. 9, the battery temperature control unit 33a inputs the altitude altm and the battery temperature tbattery (step S301).

Next, the battery temperature control unit 33a determines whether the altitude altm is equal to or higher than the altitude at which the parachute can be opened (step S302).

The parachute opening altitude is the altitude at which the closed parachute 65 can be opened to allow the multicopter 1 to descend.

If the battery temperature control unit 33a determines that the altitude altm is less than the parachute opening altitude (step S302: NO), it determines whether the value of the heating flag is "0" (step S310).

If the value of the heating flag is "0" (step S310: YES), i.e., if heating of the battery 31 has stopped, the battery temperature control unit 33a determines whether the battery temperature tbattery is lower than the predetermined temperature TC (step S311). Note that the predetermined temperature TC is a temperature higher than the predetermined temperature TA and the predetermined temperature TB, for example, 60°C. The predetermined temperature TC is the temperature at which the battery 31 is prone to deterioration.

If the battery temperature control unit 33a determines that the battery temperature tbattery is lower than the predetermined temperature TC (step S311: YES), it performs charging/discharging control (or/and heating coating 62) to heat the battery 31 (step S305), sets the value of the heating flag to "1" (step S306), and ends the process.

In this manner, in this embodiment, when the altitude altm is below the parachute opening altitude, if the battery temperature tbattery is below the predetermined temperature TC, the battery temperature control unit 33a performs charge/discharge control and/or activates the heating coating 62.

On the other hand, if the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than the predetermined temperature TC (step S311: NO), it ends the process.

In addition, in step S310, if the value of the heating flag is "1" (step S310: NO), i.e., if heating of the battery 31 is being performed, the battery temperature control unit 33a determines whether the battery temperature tbattery is equal to or higher than (predetermined temperature TC + temperature α) (step S312).

If the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than (predetermined temperature TC + temperature α) (step S312: YES), it stops heating the battery 31 by charge/discharge control (or/and the heating coating 62) (step S308), sets the value of the heating flag to "0" (step S309), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S312 that the battery temperature tbattery is less than (predetermined temperature TC + temperature α) (step S312: NO), it ends the process.

In addition, if the battery temperature control unit 33a determines in step S302 that the altitude altm is equal to or higher than the parachute opening altitude (step S302: YES), it determines whether the value of the heating flag is "0" (step S303).

If the value of the heating flag is "0" (step S303: YES), the battery temperature control unit 33a determines whether the battery temperature tbattery is less than a predetermined temperature TA (e.g., 25°C) (step S304).

If the battery temperature control unit 33a determines that the battery temperature tbattery is lower than the predetermined temperature TA (step S304: YES), it performs charging/discharging control (or/and heating coating 62) to heat the battery 31 (step S305), sets the value of the heating flag to "1" (step S306), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S304 that the battery temperature tbattery is equal to or higher than the predetermined temperature TA (step S304: NO), it ends the process.

In addition, in step S303, if the value of the heating flag is "1" (step S303: NO), i.e., if heating of the battery 31 is being performed, the battery temperature control unit 33a determines whether the battery temperature tbattery is equal to or higher than (predetermined temperature TA + temperature α) (step S307).

If the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than (predetermined temperature TA + temperature α) (step S307: YES), it stops heating the battery 31 through charge/discharge control (or/and the heating coating 62) (step S308), sets the value of the heating flag to "0" (step S309), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S307 that the battery temperature tbattery is less than (predetermined temperature TA + temperature α) (step S307: NO), it ends the process.

(Effects of this embodiment)
According to this embodiment, in addition to the effects described in the above embodiment, the following effects are further achieved.

According to this embodiment, the battery temperature control unit 33a performs charge/discharge control and/or activates the heating coating 62 when the altitude altm is less than the parachute opening altitude.

In this way, when the altitude altm is below the parachute opening altitude during flight of the multicopter 1, the battery temperature tbattery is raised by performing charge/discharge control and/or activating the heating coating 62, thereby improving the performance of the battery 31 in advance. Therefore, even if the engine 41 stops while the multicopter 1 is flying at an altitude below the parachute opening altitude and the remaining charge SOC is low, the aircraft 11 can be raised to an altitude above the parachute opening altitude using only the power discharged from the battery 31, and the parachute 65 can be opened to land the multicopter 1.

[Fourth embodiment]
Next, a fourth embodiment will be described.

(Explanation of the contents of control)
In this embodiment, the battery temperature control is performed by increasing the battery temperature tbattery as the remaining charge SOC becomes lower, thereby maximizing the performance of the battery 31 and avoiding a crash in an emergency. In more detail, when there is no time to fly to the destination due to a headwind or the like, the battery temperature tbattery is increased above the normal control temperature, and priority is given to maximizing the performance of the battery 31 even if deterioration of the battery 31 may occur. Specifically, the battery temperature control unit 33a performs the control shown in FIG. 10.

As shown in FIG. 10, the battery temperature control unit 33a inputs the remaining charge SOC, the remaining fuel fuel, the battery temperature tbattery, and the altitude altm (step S401).

Next, the battery temperature control unit 33a obtains the distance targetm (i.e., the target flight distance) to the destination from the GPS position information (i.e., information on the position of the multicopter 1 acquired by the position acquisition unit 67) (step S402).

Next, the battery temperature control unit 33a calculates and inputs the flight distance flim based on the remaining charge SOC measured by the remaining charge measurement unit 63, the remaining fuel fuel measured by the remaining fuel measurement unit 66, the battery temperature tbattery, and the altitude altm measured by the altitude measurement unit 64 (step S403).

Next, the battery temperature control unit 33a calculates the flight margin factor kfli using the following formula (step S404).
[Equation 1]
(kfli) (%) = (flim)/(targetm) x 100

Next, the battery temperature control unit 33a uses the map in FIG. 11 to calculate the target battery temperature ktbattery according to (based on) the remaining charge SOC and the flight margin kfli (step S405). Note that in FIG. 11, the temperatures are highest in the order of temperature T13, temperature T12, and temperature T11 (temperature T11<temperature T12<temperature T13).

Returning to the explanation of FIG. 10, the battery temperature control unit 33a then determines whether the value of the heating flag is "0" (step S406).

If the value of the heating flag is "0" (step S406: YES), the battery temperature control unit 33a determines whether the battery temperature tbattery is less than the target battery temperature ktbattery (step S407).

If the battery temperature control unit 33a determines that the battery temperature tbattery is lower than the target battery temperature ktbattery (step S407: YES), it performs charging/discharging control (or/and heating coating 62) to heat the battery 31 (step S408), sets the value of the heat generation flag to "1" (step S409), and ends the process.

In this way, in this embodiment, the battery temperature control unit 33a compares the calculated flight distance flim with the distance targetm from the position of the multicopter 1 acquired by the position acquisition unit 67 to the destination, and if it determines that the battery temperature tbattery is lower than the target battery temperature ktbattery required to reach the calculated destination, it performs charge/discharge control and/or activates the heating coating 62.

On the other hand, if the battery temperature control unit 33a determines in step S407 that the battery temperature tbattery is equal to or higher than the target battery temperature ktbattery (step S407: NO), the processing ends.

In addition, in step S406, if the value of the heating flag is "1" (step S406: NO), i.e., if heating of the battery 31 is being performed, the battery temperature control unit 33a determines whether the battery temperature tbattery is equal to or higher than (target battery temperature ktbattery + temperature α) (step S410).

If the battery temperature control unit 33a determines that the battery temperature tbattery is equal to or higher than (target battery temperature ktbattery + temperature α) (step S410: YES), it stops heating the battery 31 through charge/discharge control (or/and the heating coating 62) (step S411), sets the value of the heating flag to "0" (step S412), and ends the process.

On the other hand, if the battery temperature control unit 33a determines in step S410 that the battery temperature tbattery is less than the target battery temperature ktbattery + temperature α (step S410: NO), it ends the process.

(Effects of this embodiment)
According to this embodiment, in addition to the effects described in the above embodiment, the following effects are further achieved.

According to this embodiment, the battery temperature control unit 33a calculates the possible flight distance flim based on the remaining charge SOC measured by the remaining charge measurement unit 63, the altitude altm measured by the altitude measurement unit 64, and the remaining fuel fuel measured by the remaining fuel measurement unit 66. Then, the battery temperature control unit 33a compares the calculated possible flight distance flim with the distance targetm from the current position of the multicopter 1 to the destination acquired by the position acquisition unit 67, and performs charge/discharge control and/or activates the heating coating 62 if the possible flight distance flim is less than the distance targetm to the destination.

In this way, when the flight distance flim becomes less than the distance targetm to the destination while the multicopter 1 is flying, charging and discharging control is performed and/or the heating coating 62 is activated to raise the battery temperature tbattery and improve the performance of the battery 31, i.e., to increase the battery capacity. Therefore, even if there is no time to fly the multicopter 1 to the destination due to an emergency, for example, the flight distance flim can be extended and the multicopter 1 can reach the destination by raising the battery temperature tbattery and increasing the battery capacity.

The above-described embodiments are merely examples and do not limit the present disclosure in any way. Needless to say, various improvements and modifications are possible without departing from the spirit and scope of the present disclosure.

For example, the present disclosure can be applied to a multicopter (hybrid drone) equipped with an engine fueled by ethanol fuel, LP gas, natural gas, or the like, or a diesel engine. In addition, the multicopter does not need to be configured as a series hybrid system, and may be configured as a parallel hybrid system. In addition, the present disclosure can be applied to a single-rotor multicopter .

As a modified example of the 1-1 embodiment, for example, when the battery temperature control unit 33a is operating the heat generating coating 62 with priority, if the battery temperature tbattery measured by the battery temperature measurement unit 61 is less than a predetermined temperature TA, the charge/discharge control unit 33b may perform charge/discharge control.

1 Multicopter 11 Airframe 21 Propeller 22 Motor 23 Airframe main body 24 Arm 31 Battery
33 Control unit 33a Battery temperature control unit 33b Charging and discharging control unit 41 Engine 61 Battery temperature measurement unit 62 Heating coating 63 Remaining charge measurement unit 64 Altitude measurement unit 65 Parachute 66 Remaining fuel measurement unit 67 Position acquisition unit tbattery Battery temperature ktbattery Target battery temperature SOC Remaining charge altm Altitude fuel Remaining fuel flim Available flight distance kfli Flight margin TA, TB, TC Predetermined temperature A Predetermined time

Claims (4)

A multicopter having a hybrid system including an engine, a generator that generates electricity using the engine as a power source, and a battery that can be charged with the electricity generated by the generator,
a battery temperature measurement unit for measuring a temperature of the battery;
a battery temperature control unit that controls a temperature of the battery based on the temperature of the battery measured by the battery temperature measurement unit;
A charge/discharge control unit that performs charge/discharge control for charging or discharging the battery;
A heating unit that heats the battery,
the battery temperature control unit, when a predetermined time has elapsed since the charge/discharge control unit started to execute the charge/discharge control and the temperature of the battery measured by the battery temperature measurement unit is lower than a predetermined temperature, heats the battery by the heating unit;
the predetermined time period is shorter as the current value flowing through the battery is larger;
A multicopter that features: The multicopter of claim 1 ,
a charge remaining amount measuring unit for measuring a charge remaining amount of the battery;
An altitude measurement unit that measures the altitude of the multicopter ;
having
The battery temperature control unit is
calculating a target battery temperature based on the remaining charge measured by the remaining charge measuring unit and the altitude measured by the altitude measuring unit;
When the temperature of the battery measured by the battery temperature measurement unit is lower than the target battery temperature, the charge/discharge control unit performs the charge/discharge control and/or the heating unit heats the battery;
the target battery temperature is calculated using a map that defines a relationship between the remaining charge, the altitude, and the target battery temperature;
the map specifies that the target battery temperature becomes higher as the remaining charge becomes lower and the altitude becomes higher;
A multicopter that features: The multicopter of claim 1 ,
An altitude measurement unit that measures the altitude of the multicopter ;
With a parachute
having
The battery temperature control unit is
When the altitude measured by the altitude measurement unit is less than a parachute opening altitude at which the parachute in a closed state can be opened to descend the multicopter , the charge/discharge control unit performs the charge/discharge control, and/ or the heating unit heats the battery ;
A multicopter that features: The multicopter of claim 1 ,
a charge remaining amount measuring unit for measuring a charge remaining amount of the battery;
An altitude measurement unit that measures the altitude of the multicopter ;
a fuel remaining amount measuring unit that measures a remaining amount of fuel used to drive the engine;
A position acquisition unit that acquires a position of the multicopter ;
having
The battery temperature control unit is
Calculating a possible flight distance based on the remaining charge measured by the remaining charge measuring unit, the altitude measured by the altitude measuring unit, and the remaining amount of fuel measured by the remaining fuel measuring unit;
The calculated flight distance is compared with a target flight distance, which is a distance from the position of the multicopter acquired by the position acquisition unit to a destination;
When the possible flight distance is shorter than the target flight distance, the charge/discharge control unit performs the charge/discharge control and/ or the heating unit heats the battery ;
A multicopter that features:

Images