JP2020138594A - Multicopter - Google Patents

Abstract

To provide a multicopter capable of using fuel for drive unit driven for generating electric power without waste to lengthen a flight time.SOLUTION: In an aspect of the present disclosure, a multicopter 1 has an engine 13a driven for generating electric power, and a control unit 15 for controlling the multicopter 1. The control unit 15, in the case where a gasoline residual amount is more than a predetermined amount V1 and when it falls under at least one of the case where an SOC is equal to or less than a predetermined value C3 and the case where a lowering rate of the SOC is higher than a predetermined rate, executes control of a flight limit mode of limiting the flight of the multicopter 1.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a multicopter, which is a rotary wing aircraft equipped with a plurality of rotors (propellers).

The flying robot control system disclosed in Patent Document 1 controls to forcibly return the flying robot to a predetermined rechargeable point when the remaining battery level becomes less than a predetermined threshold value.

JP-A-2018-55463

Here, it is assumed that a multicopter is assumed in which a drive unit such as an engine is driven to charge a battery with electric power generated by a generator, and the electric power charged in the battery is used to drive a motor to rotate a propeller. Then, in such a multicopter, if the control for forcibly returning the multicopter when the remaining battery level becomes less than a predetermined threshold value is performed as in Patent Document 1, even if the fuel for the drive unit remains. , The multicopter is forcibly returned, and the flight time of the multicopter may be shortened.

Therefore, the present disclosure has been made to solve the above-mentioned problems, and provides a multicopter capable of prolonging the flight time by efficiently using the fuel for the drive unit that drives to generate electric power. The purpose is to do.

One embodiment of the present disclosure made to solve the above problems is in a multicopter having a plurality of rotors, a motor for driving the rotors, and a battery capable of charging and discharging the electric power supplied to the motors. The control unit has a drive unit that drives to generate electricity and a control unit that controls the multicopter, and the control unit is in a state where the remaining amount of fuel for the drive unit is larger than the predetermined remaining amount of fuel. , When the remaining charge of the battery is equal to or less than the first predetermined charge, and when the charge consumption of the battery per unit time is larger than the first predetermined charge, at least one of them is applicable. , The first limiting control for limiting the flight of the multicopter is performed.

According to this aspect, even when the remaining charge of the battery is low and / or when the remaining charge of the battery may be low due to the high charge consumption of the battery per unit time, the drive unit If there is a lot of fuel left for the multicopter, instead of forcibly returning the multicopter, the flight of the multicopter is restricted and continued. As a result, the fuel for the drive unit is depleted while recovering (increasing) the remaining charge of the battery by charging the battery with the electric power generated by driving the drive unit using the fuel for the drive unit. You can fly multicopters up to. Therefore, the fuel for the drive unit that drives to generate electric power can be used without waste, and the flight time of the multicopter can be lengthened.

In the above aspect, as the first limiting control, the control unit performs altitude descent control for lowering the altitude of the multicopter until the charge consumption of the battery per unit time becomes equal to or less than the second predetermined charge consumption. It is preferable to do so.

According to this aspect, since the wind speed generally increases with altitude, lowering the altitude of the multicopter weakens the wind acting on the multicopter, so that the flight request output including the electric power used for the balance control of the multicopter is lowered. Therefore, the battery charge consumption per unit time can be reduced. As a result, the battery can be charged while increasing the surplus electric power that is not consumed among the electric power generated by driving the drive unit. Therefore, the flight time of the multicopter can be increased more reliably.

In the above aspect, the control unit limits the speed of the multicopter from the altitude descent control when the altitude becomes equal to or lower than a predetermined altitude while the altitude descent control is being performed. It is preferable to switch to control.

According to this aspect, even if the battery charge consumption per unit time cannot be sufficiently reduced even if the altitude of the multicopter is lowered, the battery charge per unit time is charged by reducing the speed of the multicopter. The consumption can be further reduced. Therefore, the flight time of the multicopter can be further extended.

In the above embodiment, the control unit is in a state where the remaining amount of fuel is equal to or less than the predetermined remaining amount of fuel and the remaining amount of charge of the battery is equal to or less than the second predetermined amount of charge, and per unit time. When the charge consumption of the battery is larger than the third predetermined charge consumption, and at least one of the above is applicable, the landing control for forcibly landing the multicopter is carried out, and the first restriction control is carried out. When the landing control is carried out under the circumstances, the second predetermined charge remaining amount or the third predetermined charge consumption amount is the case where the landing control is carried out under the situation where the first limit control is not carried out. It is preferable that the setting is smaller than that.

According to this aspect, since the altitude of the multicopter is lowered in the situation where the first restriction control is performed, it becomes easy to land the multicopter itself, so that the landing control for forcibly landing the multicopter is performed. The second predetermined charge remaining amount or the third predetermined charge consumption amount, which is a threshold value at the time of the operation, is set to be small. As a result, the timing of forced landing of the multicopter can be delayed as much as possible, so that the flight time of the multicopter can be further extended.

In the above aspect, when the execution of the first restriction control is canceled, the control unit limits at least one of the maximum altitude and the maximum speed of the multicopter to be lower than before the execution of the first restriction control. It is preferable to carry out the second limiting control.

According to this aspect, it is possible to prevent the altitude and / or speed of the multicopter from becoming too high after the implementation of the first restriction control is released. Therefore, after the implementation of the first restriction control is released, the strength of the wind acting on the multicopter can be suppressed, so that the situation where the first restriction control is executed again can be suppressed. Therefore, it becomes difficult for the first restriction control to be repeatedly performed. In other words, it is possible to carry out flights according to the conditions of the external environment.

In the above aspect, the control unit sets the control degree of the second limit control based on the learning result of the charge consumption of the battery per unit time when the first limit control is performed. , Are preferred.

According to this aspect, the flight time of the multicopter can be lengthened while adapting to the state of the external environment.

According to the multicopter of the present disclosure, it is possible to prolong the flight time by efficiently using the fuel for the drive unit that is driven to generate electric power.

It is an external perspective view of the multicopter of this embodiment. It is a block diagram which shows the structure of the multicopter of this embodiment. It is explanatory drawing about the balance control during hovering. It is explanatory drawing about the balance control during hovering. It is explanatory drawing about the balance control during movement. It is explanatory drawing about the balance control during movement. It is a flowchart which shows the setting method of a flight mode. It is a time chart diagram which shows an example of the control realized by setting a flight mode based on the flowchart of FIG. 7. It is a flowchart which shows the selection method of a flight restriction mode. It is a flowchart which shows the content of control of the pattern 1 of a flight restriction mode. It is a flowchart which shows the content of the control of the flight restriction mode pattern 2 and 3. It is a flowchart which shows the content of control of the pattern 4 of a flight restriction mode. It is a flowchart which shows the content of the 1st Embodiment of the control performed at the time of canceling a flight restriction mode. It is a flowchart which shows the content of the 2nd Embodiment of the control performed at the time of canceling a flight restriction mode. It is a flowchart which shows the content of the 3rd Embodiment of the control performed at the time of canceling the flight restriction mode. It is a time chart diagram as an explanatory diagram about a predetermined value C3. It is a figure which shows the modification of the condition of step S1. It is a figure which shows the modification of the condition of step S1.

Hereinafter, embodiments of the multicopter of the present disclosure will be described.

<Overview of multicopter>
(Multicopter configuration)
As shown in FIG. 1, the multicopter 1 of the present embodiment includes an airframe 11, a battery 12, an engine power generation unit 13, a fuel tank 14, a control unit 15, and the like.

The machine body 11 includes a propeller 11a, a motor 11b, a top plate 11c, and a foot 11d. The propeller 11a is an example of the "rotor" of the present disclosure.

A plurality of propellers 11a (eight in the example shown in FIG. 1) are provided. Then, by rotating the plurality of propellers 11a at the same time, the multicopter 1 flies.

The motor 11b is provided on each propeller 11a and drives the propeller 11a. As shown in FIG. 2, the motor 11b is electrically connected to the battery 12 and the generator 13b described later via an ESC 19 (inverter (not shown)) described later and a power control unit 18. As a result, the electric power generated by the generator 13b and the electric power discharged from the battery 12 are supplied to the motor 11b via the power control unit 18 and the ESC 19.

Further, as shown in FIG. 1, a foot 11d, which is a portion that comes into contact with the multicopter 1 when the multicopter 1 lands, is provided under the top plate 11c.

The battery 12 is provided on the top plate 11c as shown in FIG. The battery 12 is a charging / discharging unit (secondary battery, storage battery) that charges / discharges electric power. As shown in FIG. 2, the battery 12 is electrically connected to the generator 13b, which will be described later, via the power control unit 18, and charges the electric power generated by the generator 13b. Further, the battery 12 is electrically connected to the motor 11b via the power control unit 18 and the ESC 19, and discharges the electric power supplied to the motor 11b. Further, the battery 12 is provided with a sensor that detects the current / voltage of the battery 12, the temperature of the battery 12, and the SOC (System Of Charge, charge rate), and the sensor sends a signal related to such information to the control unit 15. send.

As shown in FIG. 1, the engine power generation unit 13 is provided under the top plate 11c. As shown in FIG. 2, the engine power generation unit 13 includes an engine 13a and a generator (generator) 13b. The engine 13a is a power source for the generator 13b, and is, for example, a small diesel engine or a reciprocating engine. That is, the engine 13a is driven to generate electric power to be supplied to the motor 11b or the battery 12 by the generator 13b. Further, the engine 13a receives a signal for instructing the generated power from the control unit 15. The engine 13a is an example of the "driving unit" of the present disclosure.

As shown in FIG. 1, the fuel tank 14 is provided on a tank fixing base 16 provided on the top plate 11c. The fuel tank 14 stores fuel (for example, gasoline) used to drive the engine 13a. As shown in FIG. 2, a level sensor (not shown) provided in the fuel tank 14 sends a signal regarding information on the remaining amount of fuel to the control unit 15.

As shown in FIG. 1, the control unit 15 is provided on the top plate 11c. The control unit 15 is configured as a small computer and controls the entire multicopter 1. For example, the control unit 15 controls the drive of the engine 13a to control the power generation of the generator 13b.

Further, as shown in FIG. 2, the multicopter 1 has an FC (flight controller) 17, a power control unit 18, an ESC (Electric Speed Controller) 19, a controller 20, and various sensors 21.

The FC17 is a device that controls the flight of the multicopter 1. The FC17 sends a thrust instruction signal to the control unit 15 and the ESC 19, while receiving a signal related to SOC information from the control unit 15. Further, the FC17 receives a signal of a user's operation instruction from the controller 20, and receives a signal related to the information of the detection result from various sensors 21.

The power control unit 18 is a device that controls the electric power supplied to the motor 11b. The power control unit 18 receives the electric power generated by the generator 13b, supplies and receives the electric power to and from the battery 12, and supplies the electric power to the ESC 19. Further, the power control unit 18 receives a charge / discharge switching instruction signal from the control unit 15.

The ESC 19 is a device that controls the rotation speed of the motor 11b. The ESC 19 supplies the electric power supplied from the power control unit 18 to the motor 11b as driving electric power. Further, the ESC 19 receives a thrust instruction signal from the FC17.

Further, the controller 20 is an operation unit possessed by the user of the multicopter 1, and is, for example, a joystick. Further, the various sensors 21 are sensors that detect altitude, attitude, latitude, longitude, acceleration, obstacles, and the like.

Further, in the multicopter 1 of the present embodiment, a series hybrid system is configured by the motor 11b, the battery 12, and the engine 13a. That is, in the multicopter 1, a system is configured in which the engine 13a is used only for power generation, the motor 11b is used for driving the propeller 11a, and the battery 12 for recovering the electric power is further provided. In this way, the multicopter 1 flies by generating electricity with the generator 13b driven by the engine 13a and driving the motor 11b with the generated power to drive the propeller 11a. Further, the multicopter 1 temporarily stores the surplus electric power generated by the generator 13b by driving the engine 13a in the battery 12, and uses it for driving the motor 11b as needed.

(Action of multicopter)
The multicopter 1 having such a configuration flies by supplying electric power to the motor 11b and rotating a plurality of propellers 11a. Then, by controlling the rotation speed of the propeller 11a and balancing the lift obtained by the rotation of the propeller 11a with the gravity of the multicopter 1 itself, it is possible to realize hovering flight and forward / backward / left / right movement flight of the multicopter 1. .. Further, the lift generated by the propeller 11a can be increased to realize the ascending flight of the multicopter 1, and the lift generated by the propeller 11a can be decreased to realize the descending flight of the multicopter 1. Further, by controlling the rotation speed of each propeller 11a to cause an imbalance in the lift generated by the rotation of the plurality of propellers 11a, it is possible to realize forward / backward / left / right movement flight of the multicopter 1. Then, by providing a difference in the number of rotations of the opposing propellers 11a, turning (rotation) flight can be realized.

(About multicopter balance control)
Here, the balance control of the multicopter 1 will be described. First, when the multicopter 1 is hovering (during hovering (flying)), as shown in FIG. 3, the balance control is performed so that the lifts LFA and LFB obtained by the rotation of the propeller 11a and the gravity G are balanced. Will be done. Therefore, assuming that a strong crosswind blows from the outside while the multicopter 1 is hovering in this way, a force FA that tries to roll over the multicopter 1 acts on the wind. Therefore, in order to prevent the multicopter 1 from rolling over and obtain a force for maintaining hovering on the spot, balance control is performed so as to increase the lift LFB.

Further, when the multicopter 1 is moving, as shown in FIG. 5, the movement (flying) of the multicopter 1 causes a relative air resistance to be received by the multicopter 1. Then, at this time, lift LFA and LFB are generated so as to balance the force FB due to the air resistance (that is, the force acting on the multicopter 1 due to the air resistance) and the gravity G to control the balance. Therefore, assuming that the multicopter 1 receives a strong air resistance due to a headwind as shown in FIG. 6 when the multicopter 1 is moving in this way, the force FB due to the air resistance increases. Therefore, the lift LFA and LFB are increased by the amount of the increase in the force FB due to the air resistance, and the airframe 11 (multicopter 1) is also tilted diagonally to perform balance control.

<About flight mode>
At high altitudes, the wind is strong (the wind speed is high). Therefore, when the flight altitude Z of the multicopter 1 is high, the wind acting on the multicopter 1 becomes strong, so that the flight request output of the multicopter 1 (the output required for the multicopter 1 to fly) becomes high. That is, the driving power of the motor 11b required for performing balance control of the multicopter 1 and the like increases. Therefore, of the electric power generated by the generator 13b by driving the engine 13a, the surplus electric power not consumed by driving the motor 11b is reduced, and the electric power charged to the battery 12 is reduced, so that the battery 12 per unit time is reduced. Charge consumption (discharge amount) increases. That is, the rate of decrease in SOC increases. As a result, even if gasoline remains in the fuel tank 14, the SOC may be depleted (becomes 0) and the flight time of the multicopter 1 may be shortened. Even when the multicopter 1 is moved (that is, forward / backward / left / right movement flight), the wind acting on the multicopter 1 becomes stronger, so that the flight request output of the multicopter 1 becomes higher.

Therefore, in the present embodiment, as the flight mode of the multicopter 1, a flight restriction mode is provided in addition to the normal mode, the forced return mode, and the forced landing mode. Then, the control unit 15 controls the flight mode calculated and set based on the flowchart shown in FIG. 7.

As shown in FIG. 7, the control unit 15 is in a state where the remaining amount of gasoline (the remaining amount of gasoline in the fuel tank 14) is larger than the predetermined amount V1 (the remaining amount of the predetermined fuel) and the SOC (the remaining amount of the battery 12). Control of the flight restriction mode (first) that restricts the flight of the multicopter 1 when the condition that the condition is met when the predetermined value C3 (first predetermined remaining charge) or less is satisfied (step S1: YES). Limit control) is performed (step S2).

Here, the control of the flight restriction mode is a control for limiting the flight of the multicopter 1 by lowering the flight altitude Z and the flight speed V of the multicopter 1, as will be described in detail later.

The predetermined amount V1 is, for example, an amount corresponding to 10% when the amount of gasoline in the fuel tank 14 when the tank is full is 100%. The predetermined value C3 is, for example, 10%. In the condition of step S1, instead of the predetermined value C3, the predetermined value C2 described later may be used.

Further, the control unit 15 does not correspond to the condition of step S1 (step S1: NO), but corresponds to the case where the remaining amount of gasoline is a predetermined amount V1 or less and the SOC is a predetermined value C2 or less. If the condition is satisfied (step S3: YES), the forced feedback mode is controlled (step S4). Here, the control of the forced feedback mode is a control for forcibly returning the multicopter 1 to a predetermined place (for example, the place of the departure place). The predetermined value C2 is larger than the predetermined value C3, for example, 20%.

Further, although the control unit 15 does not correspond to the condition of step S3 (step S3: NO), the remaining amount of gasoline is a predetermined amount V1 or less, and the SOC is a predetermined value C3 (second predetermined remaining charge amount). ) When the condition corresponding to the following is satisfied (step S5: YES), the forced landing mode control (landing control) is performed (step S6). Here, the control of the forced landing mode is a control for forcibly landing the multicopter 1 at a predetermined place (for example, the current location).

Further, when the condition of step S5 is not satisfied (step S5: NO), the control unit 15 controls the normal mode (step S7). Here, the control of the normal mode is a control for flying the multicopter 1 in a normal state without restricting the flight of the multicopter 1. When the control unit 15 controls the normal mode, the control unit 15 changes from the battery charge mode (mode for charging the battery 12) to the battery discharge mode (mode for discharging the battery 12) when the SOC becomes larger than the predetermined value C1. ), And when the SOC becomes C2 or less, the battery discharge mode is switched to the battery charge mode. It is assumed that the predetermined value C1 is larger than the predetermined value C2.

FIG. 8 shows a time chart diagram showing an example of control realized by setting the flight mode based on the flowchart of FIG. 7. As shown in FIG. 8, the flight request output becomes high at time T1, and the engine output is set to high mode (HI) at time T2. After that, in a state where the remaining amount of gasoline is larger than the predetermined amount V1 at the time T3, the SOC becomes the predetermined value C3 or less, so that the flight restriction mode is controlled. As a result, the flight request output becomes low, and the SOC recovers (rises). After that, at time T4, the SOC reaches a predetermined value C1, the engine output is set to the low mode (LOW), the flight restriction mode control is finished, and the normal mode control is performed. After that, at time T5, the remaining amount of gasoline becomes a predetermined amount V1 or less, and further, the SOC becomes a predetermined value C3 or less, so that the forced landing mode is controlled. Then, at time T6, the multicopter 1 lands. Then, at this time, the remaining amount of gasoline becomes 0. In this way, the flight time H of the multicopter 1 can be lengthened by flying the multicopter 1 until the gasoline is depleted while preventing the SOC from being depleted.

<About control of flight restriction mode>
Next, the content of the control of the flight restriction mode will be described. First, as control of the flight restriction mode, control for lowering the flight altitude Z (altitude descent control) can be considered. That is, in general, the higher the sky, the stronger the wind (the higher the wind speed), and the higher the flight altitude Z, the stronger the wind acting on the multicopter 1, and the higher the flight request output. Therefore, by implementing the control to lower the flight altitude Z as the control of the flight restriction mode, the wind acting on the multicopter 1 can be weakened and the flight request output can be suppressed.

Further, as the control of the flight restriction mode, the control of lowering the flight speed V can be considered. That is, the higher the flight speed V, the stronger the wind acting on the multicopter 1, and the higher the flight request output. Therefore, by implementing the control to lower the flight speed V as the control of the flight restriction mode, the wind acting on the multicopter 1 can be weakened and the flight request output can be suppressed.

In this way, for example, even when the multicopter 1 is affected by the sudden wind and the flight request output becomes high and the SOC decreases, in the present embodiment, the control unit 15 controls the flight restriction mode. Is carried out to reduce the flight altitude Z and / or the flight speed V. Then, the flight restriction mode is controlled until the influence of the wind subsides, and the flight request output is suppressed. As a result, the flight time of the multicopter 1 can be lengthened by charging the battery 12 with electric power to recover (increase) the SOC. Therefore, the multicopter 1 can be reliably flown to the destination.

Therefore, the content of the control of the flight restriction mode will be described more specifically.

In the present embodiment, as shown in FIG. 9, the control unit 15 selects any of the controls of patterns 1 to 4 as the control of the flight restriction mode.

As shown in FIG. 9, when the multicopter 1 is hovering (hovering) (step S11: YES), the control unit 15 controls the pattern 1 as the control of the flight restriction mode (step S12). ).

Further, when the multicopter 1 is not hovering (step S11: NO), the control unit 15 determines whether or not the multicopter 1 is flying at a low speed (for example, flying at a speed of less than 30 km / h) (step S11: NO). Step S13).

Then, when the multicopter 1 is flying at a low speed (step S13: YES) and there is an obstacle around the multicopter 1 (step S14: YES), the control unit 15 is in the flight restriction mode. Pattern 2 is controlled as control (step S15).

On the other hand, when the multicopter 1 is flying at a low speed (step S13: YES) and there is no obstacle around the multicopter 1 (step S14: NO), the control unit 15 is in the flight restriction mode. Pattern 3 is controlled as control (step S16).

Further, when the multicopter 1 is not hovering (step S11: NO) and the low-speed flight is not performed (step S13: NO), the control unit 15 has a pattern as control of the flight restriction mode. 4 is controlled (step S17).

Next, the contents of control of patterns 1 to 4 will be described.

(Pattern 1)
First, in the control of the pattern 1, as shown in FIG. 10, the control unit 15 lowers the flight altitude Z (from the current flight altitude Z) by an altitude ΔZ (a predetermined amount of change in altitude) (step S21). Next, when the SOC reduction speed is higher than 0 (step S22: NO), the control unit 15 determines whether or not the flight altitude Z is less than the altitude ΔZ (step S23). Here, the "SOC reduction rate" is the rate at which the SOC decreases, and is the charge consumption of the battery 12 per unit time. Further, "when the SOC decrease rate is higher than 0" means that the SOC decreases with the passage of time.

Next, when the flight altitude Z is not less than the altitude ΔZ (step S23: NO), that is, when the flight altitude Z is the altitude ΔZ or more, the control unit 15 returns to step S21 and further increases the flight altitude Z. The altitude is lowered by ΔZ (step S21).

On the other hand, when the SOC reduction speed is 0 or less in step S22 (step S22: YES), the control unit 15 performs a low altitude flight in which the multicopter 1 flies at the flight altitude Z set in step S21 (step). S24). In this way, the control unit 15 lowers the flight altitude Z to continue the flight (hovering flight) of the multicopter 1. Here, "when the SOC decrease rate is 0 or less" means that the SOC has not decreased, the SOC has been maintained, or the SOC has increased with the passage of time.

In this way, in the control of the pattern 1, the control unit 15 controls the flight restriction mode until the SOC reduction speed becomes 0 or less, that is, the charge consumption of the battery 12 per unit time is the predetermined charge consumption. The flight of the multicopter 1 is restricted by performing altitude descent control for lowering the flight altitude Z until the flight altitude becomes equal to or less than (the second predetermined charge consumption amount smaller than the first predetermined charge consumption amount).

In step S23, when the flight altitude Z is less than ΔZ (step S23: YES), the control unit 15 is considered to be significantly affected by the disturbance and difficult to maintain the flight. Therefore, the multicopter 1 Land (step S25).

(Pattern 2)
In the control of the pattern 2, as shown in FIG. 11, the control unit 15 lowers the flight altitude Z by the altitude ΔZ (step S31), and when the SOC lowering speed is higher than 0 (step S32: NO), the flight altitude It is determined whether or not Z is less than a predetermined altitude (Z1 + ΔZ) (step S33). Here, the altitude Z1 is a predetermined altitude equal to or higher than the height of the highest obstacle in the surrounding area. The highest obstacle in the vicinity is the obstacle that is confirmed to be the highest in the vicinity of the multicopter 1 when the altitude of the surrounding obstacle is confirmed by a camera (not shown) mounted on the multicopter 1.

Next, the control unit 15 returns to step S31 when the flight altitude Z is not less than the predetermined altitude (Z1 + ΔZ) (step S33: NO), that is, when the flight altitude Z is equal to or higher than the predetermined altitude (Z1 + ΔZ). , The flight altitude Z is further lowered by the altitude ΔZ (step S31).

On the other hand, when the SOC reduction speed is 0 or less in step S32 (step S32: YES), the control unit 15 performs a low altitude flight in which the multicopter 1 flies at the flight altitude Z set in step S31 (step). S34). In this way, the control unit 15 lowers the flight altitude Z to continue the flight of the multicopter 1.

Further, in step S33, when the flight altitude Z is less than the predetermined altitude (Z1 + ΔZ) (step S33: YES), the control unit 15 sets the flight speed V (current flight speed) without lowering the flight altitude Z. The speed ΔV (predetermined amount of change in speed) is lowered (step S35) than V. That is, the control unit 15 switches from altitude descent control to speed limit control for control of the flight restriction mode.

Next, when the SOC reduction speed is higher than 0 (step S36: NO), the control unit 15 determines whether or not the flight speed V is less than the speed ΔV (step S37).

Then, when the flight speed V is not less than the speed ΔV (step S37: NO), that is, when the flight speed V is greater than or equal to the speed ΔV, the control unit 15 returns to step S35 to further increase the flight speed V. ΔV is lowered (step S35).

On the other hand, when the SOC reduction speed is 0 or less in step S36 (step S36: YES), the control unit 15 sets the multicopter 1 at the flight altitude Z set in step S31 and the flight speed set in step S35. Low altitude and low speed flight is performed by V (step S38). In this way, the control unit 15 lowers the flight altitude Z and the flight speed V to continue the flight of the multicopter 1.

In step S37, when the flight speed V is less than the speed ΔV (step S37: YES), the control unit 15 is considered to be significantly affected by the disturbance and difficult to maintain the flight. Land the multicopter 1 in the field (step S39).

In this way, in this embodiment, when the flight altitude Z becomes less than the predetermined altitude (Z1 + ΔZ) when the altitude descent control is performed as the control of the flight restriction mode, the control unit 15 determines. The altitude descent control is switched to the speed limit control, and the multicopter 1 is flown while limiting the flight speed V at the flight altitude Z at that time. Alternatively, the control unit 15 makes the multicopter 1 land on the spot depending on the situation.

(Pattern 3)
In the control of the pattern 3, the control unit 15 determines in step S33 shown in FIG. 11 whether or not the flight altitude Z is less than the predetermined altitude (Z2 + ΔZ), which is different from the control of the pattern 2 (step S33). .. Here, the altitude Z2 is an altitude learned as an altitude at which the multicopter 1 can be landed immediately, and is, for example, an altitude at which the descent speed has begun to slow down during landing control of the multicopter 1 in the past. The learning of altitude Z2 is performed every time the multicopter 1 lands.

In this way, in the control of the pattern 3, when the flight altitude Z becomes less than the predetermined altitude (Z2 + ΔZ) when the altitude descent control is performed as the control of the flight restriction mode, the control unit 15 , The altitude descent control is switched to the speed limit control, and the multicopter 1 is flown while limiting the flight speed V at the flight altitude Z at that time. Alternatively, the control unit 15 makes the multicopter 1 land on the spot depending on the situation.

(Pattern 4)
The control of the pattern 4 is a control that limits the flight speed V before the flight altitude Z. In the control of the pattern 4, as shown in FIG. 12, the control unit 15 reduces the flight speed V by the speed ΔV (step S41). Next, when the SOC reduction speed is higher than 0 (step S42: NO), the control unit 15 determines whether or not the flight speed V is less than the speed ΔV (step S43).

Then, when the flight speed V is not less than the speed ΔV (step S43: NO), that is, when the flight speed V is greater than or equal to the speed ΔV, the control unit 15 returns to step S41 to further increase the flight speed V. ΔV is lowered (step S41).

On the other hand, when the SOC reduction speed is 0 or less in step S42 (step S42: YES), the control unit 15 performs low-speed flight in which the multicopter 1 flies at the flight speed V set in step S41 (step S44). ). In this way, the control unit 15 lowers the flight speed V to continue the flight of the multicopter 1.

Further, when the flight speed V is less than the speed ΔV in step S43 (step S43: YES), the control unit 15 sets the flight speed V to 0 and lowers the flight altitude Z by the altitude ΔZ (step S45). Next, when the SOC reduction speed is higher than 0 (step S46: NO), the control unit 15 determines whether or not the flight altitude Z is less than the altitude ΔZ (step S48).

Then, when the flight altitude Z is not less than ΔZ (step S48: NO), that is, when the flight altitude Z is ΔZ or more, the control unit 15 returns to step S45 and further lowers the flight altitude Z by the altitude ΔZ. (Step S45).

On the other hand, when the SOC reduction speed is 0 or less in step S46 (step S46: YES), the control unit 15 performs a low altitude hovering flight in which the multicopter 1 is hovered at the flight altitude Z set in step S45. (Step S47). In this way, the control unit 15 lowers the flight altitude Z and performs hovering flight of the multicopter 1.

In step S48, when the flight altitude Z is less than the altitude ΔZ (step S48: YES), the control unit 15 is considered to be significantly affected by the disturbance and difficult to maintain the flight. Land 1 on the spot (step S49).

<When the flight restriction mode is canceled>
In the present embodiment, when the SOC recovers (rises) to some extent, the flight restriction mode control is canceled and the normal mode control is performed. Here, when the flight restriction mode is released, the flight altitude Z and the flight speed V are returned to the original values before the control of the flight restriction mode is released. The acting wind becomes stronger, the flight request output becomes higher, and the flight restriction mode may be repeatedly controlled.

Therefore, in the present embodiment, when the flight restriction mode is released, the flight altitude Z and the flight speed V are prevented from returning to the original values before the control of the flight restriction mode is performed. Specifically, the control unit 15 executes the control of the following embodiment as the control to be executed when the flight restriction mode is released.

(First Example)
This embodiment is an example in which only the flight altitude Z is restricted at the time of performing the control of the flight restriction mode. In this embodiment, as shown in FIG. 13, the control unit 15 determines the return altitude Za from the change in the SOC change rate (change in the charge consumption of the battery 12 per unit time) when the flight restriction mode control is executed. Calculate (step S51). Here, when calculating the return altitude Za, for example, the flight time of the multicopter 1 when the user (user) flew the multicopter 1 in the past is stored, and the flight time of the multicopter 1 is supported. The return altitude Za is calculated so that the SOC change rate is possible. Next, the control unit 15 sets the flight altitude Z to the return altitude Za (step S52), and causes the multicopter 1 to fly at the return altitude Za. Then, the control unit 15 executes control (second restriction control) that limits the maximum value of the flight altitude Z (maximum altitude of the multicopter 1) to be lower than before the control of the flight restriction mode is executed (step S53).

In this way, in the present embodiment, when the control unit 15 cancels the control of the flight restriction mode, the control unit 15 limits the maximum value of the flight altitude Z to a lower value than before the control of the flight restriction mode. To carry out. Then, the control unit 15 sets the control degree (maximum value of the flight altitude Z) of the control (second restriction control) in step S53 based on the learning result of the SOC change rate at the time of executing the control of the flight restriction mode. To do.

(Second Example)
This embodiment is an example in which only the flight speed V is restricted when the flight restriction mode is controlled. In this embodiment, as shown in FIG. 14, the control unit 15 calculates the return speed Va (parallel transport speed at the time of return) from the change in the SOC change rate when the flight restriction mode control is executed (step S61). Here, when calculating the return speed Va, for example, the flight time of the multicopter 1 when the user has flown the multicopter 1 in the past is stored, and the SOC change corresponding to the flight time of the multicopter 1 is memorized. The return speed Va is calculated so as to be a rate. Next, the control unit 15 sets the flight speed V to the return speed Va (step S62), and causes the multicopter 1 to fly at the return speed Va. Then, the control unit 15 executes control (second restriction control) that limits the maximum value of the flight speed V (maximum speed of the multicopter 1) to be lower than before the control of the flight restriction mode is executed (step S63).

In this way, in the present embodiment, when the control unit 15 cancels the control of the flight restriction mode, the control unit 15 limits the maximum value of the flight speed V to be lower than that before the control of the flight restriction mode is executed. To carry out. Then, the control unit 15 sets the control degree (maximum value of the flight speed V) of the control (second limit control) in step S63 based on the learning result of the SOC change rate at the time of executing the control of the flight restriction mode. To do.

(Third Example)
This embodiment is an example in which the flight altitude Z and the flight speed V are restricted when the flight restriction mode is set. In this embodiment, as shown in FIG. 15, the control unit 15 calculates the return altitude Za and the return speed Va from the change in the SOC change rate when the flight restriction mode control is executed (step S71). Next, the control unit 15 sets the flight altitude Z to the return altitude Za and the flight speed V to the return speed Va (step S72), and causes the multicopter 1 to fly at the return altitude Za and the return speed Va. Then, the control unit 15 executes control (second restriction control) that limits the maximum value of the flight altitude Z and the maximum value of the flight speed V to be lower than before the control of the flight restriction mode is executed (step S73).

In this way, in the present embodiment, when the control unit 15 cancels the control of the flight restriction mode, the control unit 15 controls the flight restriction mode with respect to the maximum value of the flight altitude Z and the maximum value of the flight speed V. Implement control to limit it lower than before. Then, the control unit 15 determines the control degree (maximum value of flight altitude Z and flight speed) of the control (second limit control) in step S73 based on the learning result of the SOC change rate at the time of executing the control of the flight restriction mode. Maximum value of V) is set.

<Regarding the predetermined value C3>
When the flight restriction mode is controlled and the flight altitude Z is lowered, it becomes easier to land the multicopter 1 as compared with the case where the flight restriction mode is not controlled. Therefore, in the present embodiment, when the forced landing mode is controlled under the condition that the flight restriction mode is controlled, the predetermined value C3, which is the threshold value when the forced landing mode is controlled, is set to fly. Set it smaller than when controlling the forced landing mode when the restricted mode control is not performed. Therefore, the predetermined value C3 will be described with reference to an example of a time chart as shown in FIG.

As shown in FIG. 16, at time T11, the remaining amount of gasoline was greater than the predetermined amount V1 and the SOC became the predetermined value C2 or less, so that the flight mode of the multicopter 1 was set to the flight restriction mode. The flight altitude Z is lowered by the altitude ΔZ (altitude descent control is performed). Here, the SOC condition in step S11 of FIG. 7 is a condition that corresponds to the case where the SOC is a predetermined value C2 or less.

After that, from time T12 to time T14, since the SOC reduction speed is larger than 0 and the flight altitude Z is larger than 0, the flight altitude Z is lowered by the altitude ΔZ (altitude descent control is performed). Then, after the time T14, the SOC reduction rate became 0 or less, that is, as a result of the flight of the multicopter 1 being restricted, the battery 12 was charged with electric power and the SOC increased (SOC reduction rate was 0). Since it becomes (0 or a negative value) below, low altitude flight is performed at the flight altitude Z set at time T14.

After that, at time T15, the remaining amount of gasoline becomes V1 or less while the SOC is a predetermined value C2 or less, so that the flight mode of the multicopter 1 is set to the forced feedback mode.

After that, at time T16, the remaining amount of gasoline becomes 0 and the engine output becomes insufficient, so that the SOC begins to decrease. After that, at time T17, the SOC became a predetermined value C3 or less, so the flight mode of the multicopter 1 was set to the forced landing mode, and at time T18, the multicopter 1 landed.

Here, the predetermined value C3 is set to a value when the forced landing mode is implemented in a situation where the flight altitude Z is restricted by the implementation of the flight restriction mode, and is calculated by the following mathematical formula 1.
[Number 1]
C3 = a × zi

Further, the coefficient value a is a value of the SOC change rate when the flight altitude Z is lowered by the altitude ΔZx. Further, the current altitude zi is the current flight altitude Z (altitude after the flight altitude Z is lowered by the altitude ΔZx).

The coefficient value a is calculated by the following mathematical formula 2. Here, the coefficient value a is, for example, as a measured value of the SOC change rate when the flight altitude Z is lowered by the altitude ΔZx between the time T16 and the time T17, as shown by being surrounded by the broken line α in FIG. It shall be calculated. Note that ΔSOC is the amount of change in SOC when the flight altitude Z is lowered by the altitude ΔZx.
[Number 2]
a = ΔSOC / ΔZx

In this way, the predetermined value C3 is set smaller than the predetermined value C3a (see FIG. 16) when the forced landing mode is implemented in a situation where the flight altitude Z is not restricted by the implementation of the flight restriction mode. There is. That is, when the forced landing mode is controlled under the condition that the flight restriction mode is controlled, the predetermined value C3 (second predetermined charge remaining amount) is the situation where the flight restriction mode is not controlled. It is set smaller (less) than when controlling the forced landing mode below. As a result, the time at which the control of the forced landing mode is started can be delayed from the time T17a to the time T17 as shown by the arrow AR in FIG. 16, so that the flight time of the multicopter 1 can be lengthened.

<About modification>
Further, in the present embodiment, the following modifications can be considered. For example, the condition of step S1 in FIG. 7 may be a condition related to the rate of decrease in SOC (charge consumption of the battery 12 per unit time) instead of the condition related to the value of SOC. That is, the condition of step S1 is that the remaining amount of gasoline is larger than the predetermined amount V1 and the rate of decrease in SOC is higher than the predetermined speed (the charge consumption of the battery 12 per unit time is the first predetermined charge). It may be a condition that it corresponds to the case (more than the consumption amount).

Specifically, for example, as shown in FIG. 17, the condition of step S1 is that the remaining amount of gasoline is larger than the predetermined amount V1 and the wind speed at the flight altitude Z is the predetermined value W1 (for example, 15 m /). It may be a condition that it corresponds to the case where it is larger than s). Further, for example, as shown in FIG. 18, the condition of step S1 is when the remaining amount of gasoline is larger than the predetermined amount V1 and the motor output difference is larger than the predetermined value M1 (for example, 500 W). The condition may be applicable. Here, the motor output difference is the difference between the maximum value and the minimum value of the motor output, that is, the output value of the motor 11b having the maximum motor output (power for driving the motor 11b) among the motors 11b. This is the difference between (power) and the output value (power) of the motor 11b having the smallest motor output.

The condition in step S1 may be both a condition relating to the SOC value and a condition relating to the rate of decrease in SOC. That is, the condition of step S1 corresponds to the case where the remaining amount of gasoline is more than the predetermined amount V1 and the SOC is the predetermined value C3 or less, and the rate of decrease of the SOC is higher than the predetermined speed. It may be a condition.

<About the action and effect of this embodiment>
As described above, in the multicopter 1 of the present embodiment, the control unit 15 is in a state where the remaining amount of gasoline is more than the predetermined amount V1 and the SOC is a predetermined value C3 or less, and the SOC decrease speed is lower than the predetermined speed. If is also high, control of the flight restriction mode is performed when at least one of them is applicable.

In this way, when the SOC is low (when the remaining charge of the battery 12 is low) and / or because the SOC reduction rate is high (because the charge consumption of the battery 12 is high per unit time), the SOC is low. Even if there is a risk, if a large amount of gasoline remains in the fuel tank 14, the multicopter 1 is not forcibly returned, but the flight of the multicopter 1 is continued while being restricted. As a result, the gasoline in the fuel tank 14 is depleted while recovering (increasing) the SOC by driving the engine 13a using the gasoline in the fuel tank 14 and charging the battery 12 with the electric power generated by the generator 13b. The multicopter 1 can be flown up to. Therefore, the gasoline in the fuel tank 14 can be used without waste, and the flight time of the multicopter 1 can be lengthened.

Further, the higher the flight altitude Z, the stronger the wind acting on the multicopter 1, so that the electric power used for the balance control of the multicopter 1 increases. Therefore, the control unit 15 lowers the flight altitude Z until the SOC reduction speed (charge consumption of the battery 12 per unit time) becomes 0 (second predetermined charge consumption) or less as control of the flight restriction mode. Enforce control.

In this way, since the wind speed generally increases with altitude, lowering the flight altitude Z weakens the wind acting on the multicopter 1, so that the flight request output including the electric power used for the balance control of the multicopter is lowered. Therefore, the SOC reduction rate can be reduced (the charge consumption of the battery 12 per unit time can be reduced). As a result, the battery 12 can be charged while increasing the surplus electric power that is not consumed among the electric power generated by the generator 13b by driving the engine 13a. Therefore, the flight time of the multicopter 1 can be increased more reliably. In addition, the flight of the multicopter 1 can be continued even after the control of the flight restriction mode is canceled.

Further, by lowering the flight speed V, the wind acting on the multicopter 1 is weakened, so that the flight request output can be lowered and the SOC reduction speed can be lowered. Therefore, the control unit 15 limits the flight speed V from the altitude descent control when the flight altitude Z becomes a predetermined altitude Z1 (or Z2) or less while the altitude descent control is being performed. Switch to and implement.

In this way, even if the SOC reduction speed cannot be sufficiently lowered (the charge consumption of the battery 12 per unit time is sufficiently reduced) even if the flight altitude Z is lowered, the flight speed V is lowered. As a result, the SOC reduction rate can be further reduced (the charge consumption of the battery 12 per unit time can be further reduced). Therefore, the flight time of the multicopter 1 can be further extended.

Further, when the flight restriction mode is controlled and the flight altitude Z is controlled to be low, it becomes easier to land the multicopter 1 as compared with the case where the flight restriction mode is not controlled. Therefore, when the forced landing mode is controlled under the condition that the flight restriction mode is controlled, the predetermined value C3 (second predetermined charge remaining amount) is the situation where the flight restriction mode is not controlled. It is set smaller (less) than when controlling the forced landing mode below.

In this way, under the situation where the flight restriction mode is controlled, since the flight altitude Z is lowered, it becomes easy to land the multicopter 1, so that the forced landing mode is controlled. The predetermined value C3 (second predetermined remaining charge), which is the threshold value at the time, is set small (less). As a result, the timing of forcibly landing the multicopter 1 can be delayed as much as possible, so that the flight time of the multicopter 1 can be further extended.

Further, when the control of the flight restriction mode is released, the control unit 15 limits at least one of the maximum value of the flight altitude Z and the maximum value of the flight speed V to be lower than before the control of the flight restriction mode. (Ii) Implement limit control.

Thereby, the flight altitude Z and / or the flight speed V can be prevented from becoming too high after the implementation of the control of the flight restriction mode is released. Therefore, since the strength of the wind acting on the multicopter 1 can be suppressed after the control of the flight restriction mode is released, it is possible to suppress the situation where the control of the flight restriction mode is performed again. Therefore, it becomes difficult to repeatedly control the flight restriction mode.

Further, the control unit 15 determines the control degree of the second limit control (maximum value of flight altitude Z and maximum value of flight speed V) based on the learning result of the SOC reduction speed at the time of performing the control of the flight restriction mode. Set. As a result, the flight time of the multicopter 1 can be lengthened while adapting to the state of the external environment.

It should be noted that the above-described embodiment is merely an example and does not limit the present disclosure in any way, and it goes without saying that various improvements and modifications can be made without departing from the gist thereof.

For example, the condition of step S5 in FIG. 7 is that the remaining amount of gasoline is a predetermined amount V1 or less, and the rate of decrease in SOC is higher than the predetermined speed (the charge consumption of the battery 12 per unit time is the first. (Iii) It may be a condition that it corresponds to the case (more than the predetermined charge consumption amount). Alternatively, the condition of step S5 corresponds to the case where the remaining amount of gasoline is a predetermined amount V1 or less and the SOC is a predetermined value C3 or less, and the rate of decrease of the SOC is higher than the predetermined speed. It may be a condition. Then, when the forced landing mode is controlled under the condition that the flight restriction mode is controlled, the predetermined speed (third predetermined charge consumption) is under the condition that the flight restriction mode is not controlled. It may be set lower (less) than when the forced landing mode is controlled by.

Further, in the control of patterns 2 to 4 relating to the control of the flight restriction mode, the control unit 15 limits the order of the flight altitude Z limitation and the flight speed V limitation to the order shown in FIGS. 11 and 12. It's not a thing.

Further, the second predetermined charge remaining amount may be set lower than the first predetermined charge remaining amount. Further, the third predetermined charge consumption amount may be set lower than the first predetermined charge consumption amount.

The multicopter of the present disclosure can also be applied to a multicopter (hybrid drone) equipped with a fuel cell system. At this time, the fuel cell system includes a fuel cell that generates power from fuel and an oxidizing agent, a fuel supply unit (fuel injection valve (injector), etc.) that drives to supply fuel to the fuel cell, and electric power generated by the fuel cell. It has a charge / discharge part for charging / discharging. The fuel cell corresponds to the "power generation unit", the fuel supply unit corresponds to the "drive unit", and the charge / discharge unit corresponds to the "battery".

Further, the multicopter of the present disclosure can be applied to an engine using ethanol fuel, LP gas, natural gas or the like as fuel, or a multicopter (hybrid drone) equipped with a diesel engine or the like.

Further, the multicopter of the present disclosure is not limited to the multicopter in which the series hybrid system is configured, and is also applicable to the multicopter in which other hybrid systems are configured and the drone operated by engine power.

1 Multicopter 11 Aircraft 11a Propeller (rotor)
11b Motor 12 Battery 13 Engine power generation unit 13a Engine 13b Generator (generator)
14 Fuel tank 15 Control unit 20 Controller V1 Predetermined amount (predetermined remaining fuel amount)
Z Flight altitude ΔZ Altitude Z1 + ΔZ Predetermined altitude Z2 + ΔZ Predetermined altitude Za Return altitude V Flight speed Va Return speed C2 Predetermined value C3 Predetermined value

Claims (6)

In a multicopter having a plurality of rotors, a motor for driving the rotor, and a battery capable of charging and discharging electric power supplied to the motor.
A drive unit that drives to generate the electric power
It has a control unit that controls the multicopter.
The control unit
The remaining amount of fuel for the drive unit is larger than the predetermined remaining amount of fuel,
When the remaining charge of the battery is less than or equal to the first predetermined charge
and,
When the charge consumption of the battery per unit time is larger than the first predetermined charge consumption
If at least one of
Implementing the first limiting control that limits the flight of the multicopter,
A multicopter featuring. In the multicopter of claim 1,
As the first limiting control, the control unit performs altitude descent control for lowering the altitude of the multicopter until the charge consumption of the battery per unit time becomes equal to or less than the second predetermined charge consumption.
A multicopter featuring. In the multicopter of claim 2,
When the altitude falls below a predetermined altitude while the altitude descent control is being performed, the control unit switches from the altitude descent control to the speed limit control that limits the speed of the multicopter. thing,
A multicopter featuring. In the multicopter of claim 2 or 3,
The control unit
The remaining amount of fuel is equal to or less than the predetermined remaining amount of fuel.
When the remaining charge of the battery is less than or equal to the second predetermined charge
and,
When the charge consumption of the battery per unit time is larger than the third predetermined charge consumption
If at least one of
Landing control for forced landing of the multicopter was carried out.
When the landing control is carried out under the situation where the first limit control is carried out, the first limit control is not carried out for the second predetermined charge remaining amount or the third predetermined charge consumption amount. It should be set less than when the landing control is carried out under the circumstances.
A multicopter featuring. In any one of the multicopters of claims 1 to 4,
When the execution of the first restriction control is canceled, the control unit implements the second restriction control that limits at least one of the maximum altitude and the maximum speed of the multicopter to be lower than before the execution of the first restriction control. To do,
A multicopter featuring. In the multicopter of claim 5,
The control unit sets the control degree of the second limit control based on the learning result of the charge consumption of the battery per unit time when the first limit control is performed.
A multicopter featuring.

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