GB2235662A

GB2235662A - Attitude control for aircraft or marine vessels

Info

Publication number: GB2235662A
Application number: GB8920310A
Authority: GB
Inventors: Hiroshi Sato
Original assignee: Daiichi Electric Co Ltd
Current assignee: Daiichi Electric Co Ltd
Priority date: 1989-09-08
Filing date: 1989-09-08
Publication date: 1991-03-13
Anticipated expiration: 2009-09-08
Also published as: GB2235662B; GB8920310D0

Abstract

An attitude control device for an aircraft comprises an adder 1 having a control signal input Ei and a feed back signal input E, an electric rotation controller 2 for inputting an output from the adder, a rotational drive source 3 controlled by the electric rotation controller 2 and driving a two-way or a one-way fluid pressure pump 4, and a flow direction switching valve controlled by the controller 2, a fluid pressure pump 4 driven by fluid from the switching valve or the two-way type fluid pressure motor, a fluid pressure actuator 5 actuated by output of the pump 4, a flap 7 of an air craft actuated by the actuator 5, and a rotational angle sensor 6 for detecting the angle of rotation of the flap and feeding the signal back to the adder. The attitude control device is provided per each flap of the craft. Also applicable to helicopter rotor control or marine vessel rudder or fins. <IMAGE>

Description

ATTITUDE CONTROL DEVICE FOR AIR-SEA TRAFFIC TRANSPORTATION MEANS SUCH AS AIR CRAFT BACKGROUND OF THE INVENTION (Field of the Invention) This invention relates, in a broad sense, to an attitude control device for a transportation means such as an air craft or the like, and particularly to an attitude control device for an air-sea transportation means such as an air craft or the like in which a servo-motor and a fluid pressure pump are used and controlled by electronic means.

Especially, the first invention relates to an attitude control device adapted to control flaps of an air craft, the second invention relates to an attitude control device adapted to control a link mechanism of a rotor of a helicopter, and the third invention relates to an attitude control device adapted to control a rudder of a marine vessel.

(Brief Description of the Prior Art) In order to control pitch, yaw, roll, etc. by rudder, elevator, aileron, etc., a wire is used for small air crafts but a hydraulic system is employed for all large air crafts.

At present, as a supersonic air craft appears, a control means with an ability of a very quick response is required.

To this end, a hydraulic control system by means of a servo valve occupies the main stream.

The actuator control system by means of the servo valve is extremely bad in energy efficiency, so bad as about 15 30% in the common sense. For an air craft, efforts for making its body light and for improving the efficiency of its engine seem to have reached the goal. However, regarding this attitude control, it seems that because the advantages of the fluid pressure system are too valuable and the response of the servo valve is too excellent to be totally neglected, the bad efficiency is disregarded. Also, in the conventional device, pipings are disposed all over the air craft. This is far away from the fuel safe concept.

Even at present, as seen from a perspective view of an air craft of Fig. 2, a distributed control is performed by providing an actuator to each flap. Under the circumstance, even if the piping is dispersed in the best possible manner, there still remains such disadvantage as that all hydraulic pressure of that particular system is lowered when one piping is cut as long as the pump system is collectively arranged as one group. It must still be new in everybody's memory that a large passenger configured air craft was fallen on the earth because of lowered hydraulic pressure caused by breakage of piping of the control system which was caused by destruction of the pressure partition.

SUMMARY OF THE INVENTION In view of the above, an attitude control device for an air-sea transportation means such as an air craft or the like according to the present invention is designed as such that a servo-motor is driven by an electronic control means, a fluid pressure pump is driven by the servo-motor, an actuator is actuated by the fluid pressure pump, an attitude control device is actuated by the actuator, the angle of the attitude control device is converted to an electric signal and then the electric signal is fed back to the electronic control means.

The concrete construction of the attitude control device for an air-sea transportation means such as an air craft or the like according to the present invention will be described in detail.

First of all, the first invention will be described.

There is provided an adder. This adder has a control signal input and a feed back signal input as will be described.

There is also provided an electric rotation controller.

This electric rotation controller is adapted to input an output from the adder. There is further provided a rotational drive source. This rotational drive source is controlled-by the electric rotation controller. Furthermore, there is provided a two-way type fluid pressure pump. This two-way type fluid pressure pump is rotated by the rotational drive source. Instead of this two-way type fluid pressure pump, there may be provided a one-way type fluid pressure pump and a fluid flowing direction switching valve controlled by the electric rotation controller.

Furthermore, there is provided a fluid pressure actuator such as a hydraulic motor. This fluid pressure actuator is actuated by a fluid coming from the fluid flowing direction switching valve or the two-way type fluid pressure motor.

There is also provided a flap of an air craft. This flap is actuated by the fluid pressure actuator. Lastly, there is provided a rotational angle sensor. This rotational angle sensor is adapted to detect the rotational angle of the flap and feed the signal back to the adder.

The attitude control device having the above-mentioned construction is provided for each flap.

The construction of the second invention is identical with that of the first invention excepting the features mentioned hereunder. Accordingly, the description of the construction of the first invention will be hereby quoted for describing the construction of the second invention excepting the following features.

That is, the electric circuit controller of the first invention is a servo-motor. And the rotational drive source is a servo-motor. Furthermore, a pump rotated by this servo-motor is a two-way type fluid pump.

The third invention will now be described. There is provided an adder first. This adder has a control signal input and a feed back signal input as will be described.

There is also provided an electric rotation controller.

This electric rotation controller is adapted to input an output from the adder. There is further provided a rotational drive source. This rotational drive source is controlled by the electric rotation controller. Furthermore, there is provided a two-way type fluid pressure pump. This two-way type fluid pressure pump is rotated by the rotational drive source. Instead of this two-way type fluid pressure pump, there may be provided a one-way type fluid pressure pump and a fluid flowing direction switching valve controlled by the electric rotation controller.

Furthermore, there is provided a fluid pressure actuator such as a hydraulic cylinder. This fluid pressure actuator is actuated by a fluid from the fluid flowing direction switching valve or the two-way type fluid pressure motor.

There is also provided a link mechanism of a rotor of a helicopter. This link mechanism of the rotor of the helicopter is actuated by the fluid pressure actuator.

Lastly, there is provided an inclination angle sensor. This inclination angle sensor is adapted to detect the angle of inclination of the link mechanism of the rotor and feed the signal back to the adder.

The attitude control device for a helicopter having the above-mentioned construction is provided two sets as a group adapted to incline the link mechanism of the rotor of the helicopter in the X-axis and Y-axis directions.

The construction of the fourth invention is identical with that of the third invention excepting the features mentioned hereunder. Accordingly, the description of the construction of the third invention will be hereby quoted for describing the construction of the second invention excepting the following features.

That is, the electric rotation controller of the third invention is a servo amplifier. And the rotational drive source is a servo-motor. The pump rotated by this servomotor is a two-way type fluid pressure pump.

The fifth invention will now be described. There is provided an adder first. This adder has a control signal input and a feed back signal input as will be described.

There is further provided an electric rotation controller.

This electric rotation controller is adapted to input an output from the adder. There is also provided a rotational drive source. This rotational drive source is controlled by the electric rotation controller. Furthermore, there is provided a two-way type fluid pressure pump. This two-way type fluid pressure pump is rotated by the rotational drive source. Instead of this two-way type fluid pressure pump, there may be provided a one-way type fluid pressure pump and a fluid flowing direction switching valve controlled by the electric rotation controller.

Furthermore, there is provided a fluid pressure actuator such as a hydraulic cylinder. This fluid pressure actuator is actuated by a fluid coming from the fluid flowing direction switching valve or the two-way type fluid pressure pump.

There is also provided a rudder of a marine vessel.

This rudder of a marine vessel is actuated by the fluid pressure actuator. Lastly, there is provided a rotational angle sensor. This rotational angle sensor is adapted to detect the angle of rotation of the rudder or fin of a marine vessel and feed the signal back to the adder.

The construction of the sixth invention is identical with that of the fifth invention excepting the features mentioned hereunder. Accordingly, the description of the construction of the fifth invention will be hereby quoted for describing the construction of the second invention excepting the following features.

That is, the electric rotation controller of the fifth invention is a servo amplifier. And the rotational drive source is a servo-motor. The pump rotated by this servomotor is a two-way type fluid pressure pump.

As an attitude control device for an air-see transportation means such as an air craft or the like according to the present invention has the above-mentioned construction, the following effects can be obtained.

The function of the first invention will be described first. The adder inputs the control signal and the feed back signal. Then the electric rotation controller inputs the output from the adder. Thereafter, the rotational drive source is controlled by the electric rotation controller.

Then the two-way type fluid pressure pump is controlled by the rotational drive source. Instead of the two-way type fluid pressure pump, there may be provided a one-way type fluid pressure pump and the fluid flowing direction switching valve controlled by the electric rotation controller with the same effect.

Then the fluid pressure actuator such as a hydraulic motor is actuated by a fluid coming from the fluid flowing direction switching valve or the two-way type fluid pressure pump.

Thereafter, the flap of the air craft is actuated by the fluid pressure actuator. Finally, the rotational angle sensor detects the angle of rotation of the flap and feed the signal back to the adder.

An attitude control device having the above-mentioned construction is provided to each flap in order to control the attitude of the air craft.

The function of the second invention is identical with that of the first invention. Accordingly, the description of the function of the first invention excepting the features mentioned hereunder is hereby quoted for the description of the function of the second invention.

That is, as the electric rotation controller of the first invention is a servo amplifier and the rotational drive source is a servo-motor, it is controlled by servo means.

Furthermore, as the pump rotated by this servo-motor is a two-way type fluid pressure pump, the flowing direction of the fluid is determined at this stage.

The effect of the third invention will now be described.

The adder inputs the control signal and the feed back signal first. Then the electric rotation controller inputs the output from the adder. Thereafter, the rotational drive source is controlled by the electric rotation controller.

Furthermore, the two-way type fluid pressure pump is rotated by the rotational drive source. Instead of this two-way type fluid pressure pump, there may be provided a one-way type fluid pressure pump and a fluid flowing direction switching valve controlled by the electric rotation controller with the same effect.

Then the fluid pressure actuator such as a hydraulic cylinder is actuated by the fluid coming from the fluid flowing direction switching valve or the two-way type fluid pressure motor.

Thereafter, the link mechanism of the rotor of the helicopter is actuated by the fluid pressure actuator.

Finally, the rotational angle sensor detects the angle of rotation of the link mechanism of the rotor and feed the signal back to the adder.

The attitude control device for a helicopter having the above-mentioned construction is provided two sets as one group adapted to incline the link mechanism of the rotor of the helicopter in the X-axis and Y-axis directions.

The function of the fourth invention is identical with that of the third invention excepting the features mentioned hereunder. Accordingly, the description of the function of the third invention will be hereby quoted for the description of the function of the fourth invention excepting the following features.

That is, as the electric rotation controller of the third invention is a servo amplifier and the rotational drive source is a servo-motor, it is controlled by servo means.

The function of the fifth invention will now be described. The adder inputs the control signal and the feed back signal first. Then the electric rotation controller inputs the output from the adder. Thereafter, the rota tional drive source is controlled by the electric rotation controller. Furthermore, the two-way type fluid pressure pump is rotated by the rotational drive source. Instead of this two-way type fluid pressure pump, a one-way type fluid pressure pump and a fluid flowing direction switching valve controlled by the electric rotation controller may be provided with the same effect.

Then the fluid pressure actuator such as a hydraulic cylinder is actuated by the fluid coming from the fluid flowing direction switching valve or the two-way type fluid pressure pump.

Thereafter, the rudder or fin of a marine vessel is actuated by the fluid pressure actuator. Finally, the rotational angle sensor detects the angle of rotation of the rudder of a marine vessel and feeds the signal back to the adder.

The function of the sixth invention is identical with that of the fifth invention excepting the features mentioned hereunder. Accordingly, the description of the function of the fifth invention will be hereby quoted to the description of the function of the sixth invention excepting the following features.

That is, as the electric rotation controller of the fifth invention is a servo amplifier and the rotational drive source is a servo-motor, it is controlled by servo means. Furthermore, as the pump rotated by this servo-motor is a two-way type fluid pressure pump, the flowing direction of the fluid is determined at this stage.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the construction of an attitude control device for an air craft according to one embodiment of the present invention; Fig. 2 is a perspective view showing an air craft and flaps thereof; Fig. 3 is a circuit diagram showing the vicinity of an actuator according to another embodiment; Fig. 4 is a block diagram of one embodiment, in which a power servo unit includes a photo-electric converter and an optical fiber is used instead of electric wiring; Fig. 5 is a hydraulic circuit diagram showing the vicinity of one set of a hydraulic pump and a hydraulic motor according to one embodiment of the present invention wherein a plurality of power servo units are arranged in parallel relation for each flap;; Fig. 6 is a hydraulic circuit diagram showing the vicinity of one set of a hydraulic pump and a hydraulic motor according to another embodiment of the invention wherein a plurality of power servo units are arranged in parallel rela tion for each flap; Fig. 7 is a block diagram showing one example of how to combine when a plurality of computers are used for a plurality of power servo units; Fig. 8 is a schematic perspective view showing the vicinity of a rotor according to one embodiment of the invention in which the invention is applied to a helicopter; Fig. 9 is a schematic perspective view showing the vicinity of a rotor according to another embodiment of the invention in which the invention is applied to a helicopter;; Fig. 10 is an illustration of a marine vessel including means for preventing rolling and pitching, wherein Fig. 10a is a side view thereof and Fig. 10b is a rear view thereof; Fig. 11 is a side view of the marine vessel of Fig. 10 but in which the means for preventing pitching is activating; Fig. 12 is likewise a side view of the marine vessel of Fig. 10 but in which the means for preventing rolling is activating; Fig. 13 shows another embodiment for mounting a fin; Fig. 14 shows a further embodiment for mounting a fin; Fig. 15 shows a still further embodiment for mounting a fin; and Fig. 16 shows another embodiment for providing a fin.

DETAILED DESCRIPTION OF THE EMBODIMENTS One embodiment of an attitude control device for an airsea transportation means such as air crafts or the like will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic view showing the construction of an attitude control device for an air craft according to one embodiment of the present invention. The attitude control device according to this embodiment, as shown in Fig. 1, comprises a combination of an adder, a servo-amplifier, a servomotor, a hydraulic motor, and a rotational angle sensor, so that an output of the rotational angle sensor is fed back to the adder in order to obtain a power output proportional to an input.

Specifically, there is provided an adder 1 first. This adder 1 has a control signal input Ei for controlling the attitude of an air craft and a feed-back signal input Ef as will be described. Next, there is provided a servoamplifier 2. This servo-amplifier 2 is adapted to input the output of the adder 1 and amplify the signal. And, there is provided a servo-motor 3. This servo-motor 3 is rotatable in the normal and reverse directions. The rotational direction, speed, and start and stop of the servo-motor 3 are controlled by the servo-amplifier 2. Further, there is provided a hydraulic pump 4. As this hydraulic pump 4 is directly connected with the servo-motor 3, the pump 4 is rotated in the normal or reverse direction, controlled in speed, and started or stopped in accordance with the rotation of the servo-motor 3.

Furthermore, there is provided a hydraulic motor 5. As this hydraulic motor 5 is actuated by the output of the hydraulic pump 4, the motor 5 is also rotated in the normal or reverse direction, controlled in speed, and started or stopped in accordance with the rotation of the hydraulic pump 4.

Furthermore, there is provided a flap 6 of the air craft. This flap 6 is actuated by the hydraulic motor 5.

Accordingly, the flap 6 is rotated in the normal or reverse direction, controlled in speed, and started or stopped in accordance with the rotation of the hydraulic motor 5.

Lastly, there is provided a rotational angle sensor 7. This sensor 7 is adapted to detect the angle of rotation of the flap 6 and feed the signal back to the adder 1.

The above-mentioned construction is available for each of the flaps 7a through 7j.

As another embodiment, instead of the hydraulic motor 5 and the angle sensor 6, there may be used, as shown in Fig.

3, a cylinder 5a of a linear action and a displacement sensor 6a in order to convert it into a rotational motion.

If this combination (excluding the flap) is integrated, the entirety can be regarded as one actuator which is ac tuated by an electric signal. Accordingly, hereinafter this is referred to as "power support unit PSU". If a single or a plurality of power support units PSU are mounted on a single flap dispersed and remote controlled by an electric signal, it can be most approached to the concept of fuel safe.

If a photo-electric converter is added to the input of the power support unit PSU as the block diagram shown in Fig.

4, a remote control can be performed by light using an optical fiber F. Besides, there would be required the electric wiring for an electric power source for an amplifier and the electric wiring for a servo motor electric power source, these may be commonly used instead of separately wired. As this electric wiring is for the use of electric power1 it is hardly affected by outside noise. If a signal input, which is sensitive to outside noise, is performed by means of optical communication, reliability of this unit PSU is remarkably increased.

As described above, a plurality actuators are mounted with respect to a single flap 7. By virtue of the foregoing arrangement, even when one servo unit is out of order, operation will not become impossible as long as other power servo unit normally works. In this case, however, as the power servo unit, which is out of order, becomes a brake, it is desirably that oil is bypassed by a bypass valve 8 of Fig. 5 or otherwise oil is discharged into tanks 9 and 10 as shown in Fig. 6. In this case, it is possible that a plurality of power servo units PSU are not activated in parallel but one portion thereof is activated and the remainder is kept standby.

In general, an air craft usually loaded with a plurality of controlling computers for the sake of safety. In this case, it is preferable that, as the block diagram shown in Fig. 7, the computer and the servo unit are interconnected by a signal conductor by means of light or electricity in order to form a net work. Owing to the foregoing arrangement, even when the computer or the power servo unit is out of order, other computers or power servo units are immediately actuated and therefore, unless all signal conductors are cut, the flight can be continued.

It is also possible that two such power servo units are used in order to control the rotor 11 of a helicopter in the X-axis and Y-axis directions. In this case, as shown in Fig. 8, a cylinder system power servo units of linear operation may be connected with a link mechanism 12 to control two axes, or as shown in Fig. 9, two cylinders 5a may be connected with one axis in order to perform a push-pull oper-ation by one power servo unit. In this way, the advancing direction of the flight can be controlled.

Although description has been limited to an air craft in order to facilitate an easy explanation, this attitude control device can also be applied to a steering of a marine vessel. Therefore, merely by changing the term "air craft" to "marine vessel", the description so far made with respect to the air craft is hereby quoted for the marine vessel.

The term "attitude control of a marine vessel" when used herein is not limited to a controlling of its direction but also applicable to a controlling of rolling and pitching (the term "attitude" when used in this specification means "inclination" and/or "direction"). The attitude control of a marine vessel is somewhat different from the attitude control of an air craft or the like. The attitude control of a marine vessel chiefly aims at preventing an occurrence of rolling and pitching caused by wave in order to maintain a living space for a human always in a horizontal state.

This aim can be achieved by providing a pair of fins 14a through 14d at the right and left sides in the vicinity of the bow of the marine vessel 13 and at the right and left sides in the vicinity of the stern of the marine vessel 13, respectively, as shown in Fig. 10a. In this way, by moving the front and rear fins 14a and 14c, and 14b and 14d in the reverse directions respectively as shown in Fig. 11, pitching can be prevented from occurring. On the other hand, by moving the right and left fins 14a and 14b, and 14c and 14d in the reverse directions as shown in Fig. 12, rolling can be prevented from occurring.As this fin 14 becomes an obstacle when the marine vessel comes alongside the pier, it is preferable that the bow portion or the stern portion are formed in a concave shape as shown in Fig. 13 or otherwise they are mounted in such a manner as to project forward and backward of the marine vessel as shown in Fig. 14. They may also be mounted on the bottom of the marine vessel.

In this way, by determining the direction (yawing) using a rudder and preventing the rolling and pitching using a stable wing or fin 14, seasickness of crews and passengers can be greatly reduced. This fin may be formed into a shape like a wing and also may be attached with a flapper. Alternatively, as shown in Fig. 16, the number of the stable wing of either the bow or stern may be limited to one, so that the attitude control can be performed by three axes.

As described in the above, the attitude control of a marine vessel is performed as such that the stable control is performed by three or four axes and the direction control is performed by one axis, and thus by five axes in total. By performing this 4 or 5 axis control by means of a hydraulic system, there can be obtained an attitude control which is of energy saving and rapid in response. In the same manner, the attitude control of a hydrofoil craft can be performed.

Although there has been described a device in which, as shown in Fig. 17, the hydraulic pump is driven by an electric motor and the hydraulic pump and the actuator are interconnected by two pipings, this merely shows a basic example, and the same operation and effect can be obtained by a modified embodiment that will be shown hereunder.

That is, as shown in Fig. 18, it may be designed as such that one-way type hydraulic pump 4a is combined with a direction switching valve 7, the oil rate is determined by speed of rotation of the hydraulic pump 4a, and the flowing direction is determined by the switching valve 7.

The hydraulic pump 4 used in any of the above-mentioned embodiments may be of a fixed delivery type or a variable delivery type. In a case that the variable delivery type pump is used, the range of fluctuation of oil rate can exceed the range of the speed of rotation of its power source.

Regarding the electric motor, the basic example is that the servo amplifier 2 and the servo 3 are combined with each other to control the speed of rotation and the direction of the motor. However, this can be replaced with an inverter and an alternating current induced motor with the same effect. Moreover, instead of the electric motor, a power source such as an internal combustion engine,an external combustion engine or the like may be used. In this case, the speed of rotation, output, etc. of the power source are controlled by detecting the momentum (displacement, angle of rotation, speed, acceleration, etc.) of a mechanical output Po of the actuator and feeding the detected data back to the adder.

As the attitude control device of an air-sea transportation means such as an air craft according to the present invention is constructed in such a manner as mentioned above, the following effects can be obtained.

That is, the hydraulic pressure portion is so simple as that the hydraulic pump and the actuator are interconnected merely by two pipings. What are added thereto are a bypass valve, a discharge valve, a relief valve, etc. which are adapted only for the purpose of safety. In a case that the hydraulic pump and the actuator are integrally formed, these pipings can also be omitted.

As will be understood with reference to this hydraulic circuit, no element for lowering the efficiency caused by a servo valve, etc. can be found at all. The efficiency of a single unit of the hydraulic pump and the efficiency of a single unit of the actuator could remain as a small problem yet to be solved. It is said that the efficiencies of a pump and an actuator are 90% respectively. Therefore, the efficiency of the hydraulic pressure portion would be 81% even when the conventional hydraulic components are combined presuming that the resistance of the pipings is disregarded.

Therefore, the fact that energy efficiency for the use of the attitude control in order to maintain the air craft, etc.

safe is drastically improved indicates that an additional fuel can be loaded on the air craft, etc., which naturally makes it possible to increase the flying distance.

The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. An attitude control device for an air craft comprising an adder having a control signal input and a feed back signal input; an electric rotation controller for inputting an output from said adder; a rotational drive source controlled by said electric rotation controller; a two-way type or a one-way type fluid pressure pump rotated by said rotational drive source and a fluid flowing direction switching valve controlled by said electric rotation controller; a fluid pressure pump driven by fluid coming from said fluid flowing direction switching valve or said two-way type fluid pressure motor; a fluid pressure actuator actuated by output of said fluid pressure pump; a flap of an air craft actuated by said fluid pressure actuator; and a rotational angle sensor for detecting the angle of rotation of said flap and feeding the signal back to sa-id adder; said attitude control device for an air craft having the above mentioned construction being provided per each flap of the air craft.

2. An attitude control device for an air craft comprising an adder having a control signal input and a feed back signal input; a servo amplifier for inputting an output of said adder; a servo-motor rotation of which is controlled by said servo amplifier; a fluid pressure pump rotation of which is controlled by said servo-motor; a fluid pressure actuator actuated by an output of said fluid pressure pump; a flap of an air craft actuated by said fluid pressure actuator; and a rotational angle sensor for detecting the angle of rotation of said flap and feeding the signal back to said adder; said attitude control device for an air craft having the above mentioned construction being provided per each flap of the air craft.

3. An attitude control device for a helicopter comprising an adder having a control signal input and a feed back signal input; an electric rotation controller for inputting an output from said adder; a rotational drive source controlled by said electric rotation controller; a two-way type or a one-way type fluid pressure pump rotated by said rotational drive source and a fluid flowing direction switching valve controlled by said electric rotation controller; a fluid pressure pump driven by fluid coming from said fluid flowing direction switching valve or said two-way type fluid pressure motor; a fluid pressure actuator actuated by output of said fluid pressure pump a link mechanism of a rotor of a helicopter inclined by said fluid pressure actuator; and a rotational angle sensor for detecting the angle of inclination of said link mechanism of said rotor and feeding the signal back to said adder; said attitude control device for a helicopter having the above-mentioned construction being provided two sets as one group adapted to incline a link mechanism of a rotor of said helicopter in the X-axis and Y-axis directions.

4. An attitude control device for a helicopter comprising an adder having a control signal input and a feed back signal input; a servo amplifier for inputting an output from said adder; a servo-motor the rotation of which is controlled by said servo amplifier; a fluid pressure pump rotated by said servo-motor; a fluid pressure actuator actuated by output of said fluid pressure pump; a link mechanism of a rotor of a helicopter inclined by said fluid pressure actuator; and a rotational angle sensor for detecting the angle of inclination of said link mechanism of said rotor and feeding the signal back to said adder; said attitude control device for a helicopter having the above-mentioned construction being provided two sets as one group adapted to incline a link mechanism of a rotor of said helicopter in the X-axis and Y-axis directions.

5. An attitude control device for a marine vessel comprising an adder having a control signal input and a feed back signal input; an electric rotation controller for inputting an output from said adder; a rotational drive source controlled by said electric rotation controller; a two-way type or a one-way type fluid pressure pump rotated by said rotational drive source and a fluid flowing direction switching valve controlled by said electric rotation controller; a fluid pressure actuator driven by fluid coming from said fluid flowing direction switching valve or said two-way type fluid pressure motor; a rudder or a fin of a marine vessel actuated by said fluid pressure actuator; and a rotational angle sensor for detecting the angle of inclination of said rudder or fin of the marine vessel and feeding the signal back to said adder; one or two such constructed attitude control device for a marine vessel as mentioned above being provided.

6. An attitude control device for a marine vessel compris ing an adder having a control signal input and a feed back signal input; a servo amplifier for inputting an output from said adder; a servo-motor the rotation of which is controlled by said servo amplifier; a fluid pressure pump rotated by said servo-motor: a fluid pressure actuator actuated by output of said fluid pressure pump; a rudder or a fin of a marine vessel actuated by said fluid pressure actuator; and a rotational angle sensor for detecting the angle of inclination of said rudder or fin of the marine vessel and feeding the signal back to said adder; one or two such constructed attitude control device for a marine vessel as mentioned above being provided.

7. An attitude control device substantially as hereinbefore described with reference to the accompanying drawings.

8. An attitude control device for an aircraft, helicopter or marine vessel substantially as hereinbefore described with reference to the accompanying drawings.