JP2002166893A - Liquid tank loading structure for pilotless helicopter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid tank structure for a pilotless helicopter comprising several liquid tanks in which liquid is consumed and reduced during flying and allowing flying with keeping a stable attitude of the helicopter without disordering the attitude by decrease of the liquid during flying. SOLUTION: This liquid tank loading structure for the pilotless helicopter comprises several liquid tanks 8a, 8b, 12 containing the liquid to be consumed during flying, detecting means 9a, 9b of liquid volumes of the liquid tanks, liquid feeding pipes 11, 11a, 11b adapted to suck the liquid from the liquid tanks by pumps P1, P2 for feeding the liquid to a liquid consuming part, and a control device 10 adapted to control a sucked volume of the liquid from the liquid tanks by the liquid feeding pipes. The control device 10 controls the sucked volume of the liquid from the liquid tanks such that a position of center of gravity of the whole liquid tanks is kept constant in a plane view on the basis of detected data by the liquid volume detecting means 9a, 9b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a liquid tank such as a fuel tank or a chemical tank of an unmanned helicopter.

[0002]

2. Description of the Related Art In order to increase the flight distance and flight time of an unmanned helicopter, a fuel tank structure having one or two sub fuel tanks for replenishment in addition to a main fuel tank having a limited capacity is considered. Have been. In addition, in an unmanned helicopter for spraying chemicals such as agricultural chemicals, an unmanned helicopter has been developed in which a chemical solution tank is mounted on each of the right and left outer sides of the body to increase a spraying area, in order to increase a spray area.

[0003]

However, in such an unmanned helicopter having a plurality of liquid tanks, fuel is consumed by the engine during flight, the amount of fuel in the fuel tank is gradually reduced, and chemicals are not used. During the flight, the chemical liquid in the chemical liquid tank that is sprayed and consumed from the spray nozzle gradually decreases. For this reason, depending on the mounting position of the plurality of liquid tanks, the amount of suction of the liquid from each liquid tank by the pump, the suction order, and the like, the balance of the amount of liquid in each liquid tank is lost, and the center of gravity of the entire tank in plan view. Changes. The change in the position of the center of gravity affects the attitude of the aircraft, deteriorating the flight performance such as turning performance and deteriorating the controllability of driving, making it impossible to perform a stable driving operation.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned prior art, and is directed to an unmanned helicopter having a plurality of liquid tanks which are consumed during a flight and whose liquid amount gradually decreases. It is an object of the present invention to provide a liquid tank structure of an unmanned helicopter that can fly while maintaining a stable attitude without disturbing the attitude of the aircraft.

[0005]

In order to achieve the above object, according to the present invention, a plurality of liquid tanks containing liquid consumed during flight, a liquid amount detecting means of each liquid tank, and a liquid tank are provided. A liquid tank mounting structure of an unmanned helicopter, comprising: a liquid supply piping system that sucks a liquid by a pump and sends the liquid to a liquid consumption unit; and a control device that controls a liquid suction amount from each liquid tank by the liquid supply piping system. hand,
The control device controls the amount of liquid suction from each liquid tank based on the detection data of the liquid amount detection means so that the position of the center of gravity of the entire liquid tank in a plan view is kept constant. To provide an unmanned helicopter with a liquid tank mounting structure.

According to this configuration, when the liquid is suctioned from each liquid tank by the pump and sent to the consuming unit (engine or spray nozzle), the control device controls the detection data of the liquid level sensor and the like provided in each liquid tank. The amount of liquid and the position of the center of gravity of the plurality of tanks are calculated from the position and shape of each liquid tank, and the amount of liquid suction from each liquid tank is controlled so that the center of gravity is kept constant. Thus, even when the liquid surface is inclined due to the flight attitude, the liquid is suctioned from each liquid tank in a well-balanced manner, and stable flight control can be performed without disturbing the attitude of the body. At this time, when a plurality of liquid tanks having the same shape are arranged at symmetrical positions with respect to the center of gravity, the liquid level becomes uniform by calculating the liquid level without calculating the center of gravity, and the center of gravity is maintained at the same position. Dripping.

In a preferred embodiment, a bottom of the plurality of liquid tanks communicates with each other via a communication pipe, an on-off valve is provided in the middle of the communication pipe, and an inclination sensor for detecting an inclination angle of the body is provided.
The on-off valve is closed when the detection angle of the inclination sensor is equal to or larger than a predetermined value.

According to this configuration, the bottoms of the liquid tanks are connected to each other by the communication pipe, so that the liquid surfaces are aligned and the liquid amount is made uniform. At this time, if the attitude of the aircraft is greatly inclined,
Since the on-off valve of the communication pipe is closed, the liquid is prevented from temporarily temporarily being biased into one tank, and the weight balance is maintained. When the posture is returned and the inclination angle is reduced, the communication pipe is opened and the liquid level becomes uniform. If the diameter of the communication pipe is small, the effect of the communication pipe may not be sufficiently obtained depending on the flight speed and flight attitude of the aircraft, and the liquid level may be uneven. If the diameter of the communication pipe is simply increased to cope with this, a problem occurs when the inclination increases. According to the configuration of the present invention, by providing the open / close valve in the communication pipe, it is possible to provide a communication pipe having a sufficiently large diameter without causing a problem when the inclination becomes large.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view of an unmanned helicopter according to an embodiment of the present invention.

[0010] An engine 32 and a transmission 3 connected to the engine 32 in an airframe 30 of an unmanned helicopter 31
3 is mounted on the main rotor 35 via a rotor shaft 34.
Is driven to rotate. A tail rotor 39 is provided at the rear end of the fuselage, and a skid 38 is provided below the fuselage. A main tank 36 that supplies fuel to the engine 32 is provided in the body 30. In this embodiment, two sub-tanks 37a and 37b for replenishing the main tank with fuel are disposed at positions separated in the front-rear direction. Each sub tank 37a,
Fuel is supplied to the main tank 36 from the pump 37, via the pumps P1 and P2, respectively. Each tank is arranged so that the center of gravity G of the whole of the main tank 36 and the two sub-tanks 37a and 37b is almost directly below the rotor shaft 34. In the present invention, when the fuel in the main tank is reduced and the fuel is supplied from the sub tank to the main tank, the fuel is supplied from one of the sub tanks so that the position of the center of gravity G does not change in a plan view when viewed from above. For this reason, as described below,
A liquid level sensor (not shown) is provided in each of the tanks 36, 37a, and 37b. Based on this, a CPU (not shown) drives and controls the pumps P1 and P2 to maintain weight balance.

That is, when the Y axis is forward in the plane perpendicular to the rotor axis passing through the center of gravity G, and the X axis is rightward when viewed in the forward direction, the fuel remaining weight Wi of each tank and the fuel When the coordinates of the center of gravity of the remaining amount are (0, yi),
y '= ΣWiyi / ΣWi to find the center of gravity of the remaining fuel,
Drive control is performed on either or both of the pump P1 and the pump P2 so that the amount of fuel supply from the sub tank on the −y ′ side with respect to the X axis increases.

FIG. 2 is a front view of an unmanned helicopter for spraying a chemical solution. Chemical solution tanks 42a and 42b are mounted on the right and left outer sides of the body 40, respectively. A valve 49 is provided at the bottom of each chemical solution tank, and is connected to the chemical solution pump 43 via a tube 47. The discharge side of the chemical liquid pump 43 is connected to the left and right feed pipes 44 via a tube 48. A spray nozzle 45 is provided at an end of each feed pipe 44 to spray a chemical solution. Reference numeral 50 denotes a motor wiring of the chemical liquid pump 43, and reference numeral 46 denotes a coupler for connecting to a power supply and a control device in the body. The center of gravity G where the left and right chemical liquid tanks 42 a and 42 b are combined is almost immediately below the rotor shaft 41. When the two tanks are separated in the horizontal direction (left-right direction) in this manner, the position of the center of gravity G will be described later, as in the case where the two tanks are separated in the front-rear direction. Each valve 49 is driven to open and close so that does not change in a plan view, and the chemical liquid is sucked from the respective chemical liquid tanks to the pump 43 and dispersed.

FIG. 3 is a configuration diagram of an embodiment of the present invention for spraying a chemical solution. Two chemical liquid tanks 1a and 1b are mounted on a body (not shown). Each chemical liquid tank is provided with a float type liquid level sensor 2a, 2b. Each liquid level sensor is connected to a control device (CPU) 3. Each chemical solution tank 1a, 1
b is a common pump 6 via pipes 5a and 5b, respectively.
Connected to. Each pipe 5a, 5b is provided with a valve 4a, 4b driven by the CPU 3. A spray nozzle 7 is provided at the end of the pipe 5 on the discharge side of the pump 6.

In the above-described configuration, the CPU 3 operates based on the detection data from the liquid level sensors 2a and 2b.
The valves 4a and 4b are controlled to be opened and closed or flow-rate-adjusted so that the liquid levels of a and 1b are uniform. That is, assuming that the Y axis is forward in the plane perpendicular to the rotor axis and passes through the center of gravity G and the X axis is rightward when viewed in the forward direction, the remaining fuel weight Wi of each tank and the remaining fuel in each tank Let the coordinates of the center of gravity be (x
i, 0), the center of gravity of the remaining fuel amount is obtained by x ′ = ΣWixi / ΣWi, and the valve 4a is increased so that the fuel supply amount from the chemical tank on the −x ′ side with respect to the Y axis increases. ,
The opening of one of the valves 4b is increased, and the opening of the other valve is reduced so that the amount of fuel supplied from the chemical tank on the X side decreases.

Thus, the position of the center of gravity of both chemical liquid tanks 1a and 1b can be kept constant irrespective of the pipe diameter, arrangement structure, flight attitude and the like. When the shape of each chemical liquid tank is different or the position with respect to the center of gravity is not symmetric, the CPU 3 calculates the liquid weight in the tank based on the liquid level data to obtain the position of the entire center of gravity. The valves 4a and 4b are driven and controlled so as to be maintained.

The tank structure shown in FIG.
Both a case where a and 1b are mounted apart from each other in the front-back direction and a case where they are mounted separately from each other in the lateral direction are applicable. Further, the present invention can be applied to a fuel tank. In addition, only one of the pipes 5a or 5b has the valve 4a or 4b.
b may be provided and one of the valves may be omitted. Further, a pump may be provided in each of the pipes 5a and 5b instead of or together with the valve, and the flow rate may be controlled by the pump. After the chemicals from both tanks 1a and 1b join at the pipe 5, they are distributed equally to the left and right spray nozzles 7 respectively.

FIG. 4 is a configuration diagram of an embodiment in which the present invention is applied to a fuel tank. Two sub-tanks 8a, 8 are connected to a main tank 12, which supplies fuel to the engine, via pipes 11a, 11b and a pipe 11 where they join.
b is connected. Pumps P1 and P2 that are driven and controlled by the CPU 10 are provided in the respective pipes 11a and 11b. Each sub tank 8a, 8b is provided with a liquid level sensor 9a, 9b.

In such a fuel tank structure, the CPU 10 controls the driving of the pumps P1 and P2 based on the liquid level detection data in the same manner as in the example of FIG. Keep the position constant.
Note that this example is also applicable to a chemical liquid tank, and a common pump may be used, or the flow rate may be controlled by a valve instead of the pump.

FIG. 5 is a configuration diagram of still another embodiment of the present invention. This example shows a fuel tank structure,
Main tank 15 and sub tank 16
Is provided. The main tank 15 is connected to the engine 14 in the body via a pipe 19. The sub tank 16 is connected to the main tank 15 via a pipe 18. Pumps P4 and P3 are provided in the respective pipes 18 and 19, respectively. Each of the main tank 15 and the sub tank 16 is provided with a liquid level sensor 17 similarly to the above-described example.
Connected to 1. With such a configuration, the pump P is controlled so that the CPU 21 maintains the position of the center of gravity G of both tanks almost immediately below the rotor shaft 24 as in the above-described examples of FIGS.
3 and P4 are driven and controlled based on the liquid level data.

The embodiment shown in FIG. 5 further includes a body inclination sensor 20 and a main tank 1.
5 and the bottom of the sub tank 16 are communicated with each other by a communication pipe 22. The tilt sensor 20 is connected to the CPU 21. The communication pipe 22 is provided with a communication valve (open / close valve) 23 that is driven and controlled by the CPU 21.

FIG. 6 is a flowchart of an operation routine of the communication pipe shown in FIG. Airframe 1 by tilt sensor 20
3 is detected, and the detection data is input to the CPU 21 (step S1). The CPU 21 compares the tilt angle with a predetermined angle α (step S2). If the inclination angle is not more than α, the communication valve 23 is opened to connect the main tank 15 and the sub tank 16 (step S3).
If the inclination angle is larger than α, the communication valve 23 is closed (step S4). Thus, during a normal flight with a small body inclination angle, in addition to the liquid amount adjustment by drive control of the pumps P3 and P4, the liquid level of both tanks is more reliably aligned by the action of the communication pipe, and the body inclination angle is reduced. When it becomes larger than a certain level, it is possible to prevent the fuel from temporarily flowing into one of the tanks, thereby preventing the weight balance from being lost.

[0022]

As described above, according to the present invention, when a liquid is suctioned from each of a plurality of liquid tanks by a pump and sent to a consuming unit (an engine or a spray nozzle), the control unit (CPU) controls each liquid. The amount of liquid and the position of the center of gravity of the plurality of tanks are calculated from the detection data of the liquid level sensor provided in the tank and the position and shape of each liquid tank, and the liquid is suctioned from each liquid tank so that the center of gravity is kept constant. Control the amount. Thus, even when the liquid surface is inclined due to the flight attitude, the liquid is suctioned from each liquid tank in a well-balanced manner, and stable flight control can be performed without disturbing the attitude of the body.

[Brief description of the drawings]

FIG. 1 is an overall view of an unmanned helicopter to which the present invention is applied.

FIG. 2 is a front view of an unmanned helicopter for spraying a chemical to which the present invention is applied.

FIG. 3 is a configuration diagram of an embodiment of the present invention.

FIG. 4 is a configuration diagram of another embodiment of the present invention.

FIG. 5 is a configuration diagram of still another embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the embodiment of FIG. 5;

[Explanation of symbols]

1a, 1b: chemical liquid tank, 2a, 2b: liquid level sensor,
3: CPU, 4a, 4b: valve, 5, 5a, 5b: piping, 6: pump, 7: spray nozzle, 8a, 8b: sub tank, 9a, 9b: liquid level sensor, 10: CPU, 11,
11a, 11b: piping, 12: main tank, 13: body, 14: engine, 15: main tank, 16: sub tank, 17: liquid level sensor, 18: piping, 19: piping,
20: tilt sensor, 21: CPU, 22: communication pipe, 2
3: communication valve, 24: rotor shaft, 30: body, 31:
Unmanned helicopter, 32: engine, 33: transmission, 34: rotor shaft, 35: main rotor, 3
6: Main tank, 37a, 37b: Sub tank, 3
8: skid, 39: tail rotor, 40: fuselage, 4
1: rotor shaft, 42a, 42b: chemical liquid tank, 43: chemical liquid pump, 44: feed pipe, 45: spray nozzle, 46: coupler, 47: tube, 48: tube, 49: valve, 50: motor wiring.

Claims (2)

[Claims] 1. A plurality of liquid tanks containing liquid consumed during flight, liquid amount detecting means of each liquid tank, and a liquid supply pipe for sucking liquid from each liquid tank by a pump and sending the liquid to a liquid consuming unit. A liquid tank mounting structure of an unmanned helicopter, comprising: a control unit that controls a liquid suction amount from each liquid tank by the liquid supply piping system, wherein the control device detects detection data of the liquid amount detection unit. A liquid tank mounting structure for an unmanned helicopter, characterized in that the liquid suction amount from each liquid tank is controlled so that the position of the center of gravity of the entire liquid tank in a plan view is kept constant based on the. 2. The apparatus according to claim 2, further comprising a communication pipe connecting the bottoms of the plurality of liquid tanks with a communication pipe, an on-off valve provided in the middle of the communication pipe, and a tilt sensor for detecting a tilt angle of the body. The liquid tank mounting structure for an unmanned helicopter according to claim 1, wherein the on-off valve is closed when the value is equal to or more than a predetermined value.