Aircraft Control Method
The present invention provides a method for flying craft control using a control surface located in front of the centre of gravity and displaced by applying fixed controllable torque in relation to the axis of rotation of such a surface.
In the aeroplane and glider control methods that have been known so far and that are currently in use control surfaces are used that are located in front of or behind the lift-generating surface. This refers to the traditional design where control surfaces are placed in the rear section, the tail-first design where control surfaces are placed in the front section or the flying wing design or its version where delta wings are used. In order to ensure normal flight apart from the development of lift that is necessary to balance the weight of the aeroplane and enable flight control what is also necessary is ensuring a minimum level of flight stability in respect of all the three axes. Excepting computer systems with artificial stability it can be said that the necessary margin of stability can be ensured naturally by correctly placing the centre of gravity of the aeroplane or glider. This correct placing means that the centre of gravity should be moved far enough to the front section where it is in front of the resultant aerodynamic forces acting on the aeroplane. This implies that there is a significant deficiency present in the solutions used so far, namely that in most cases in order to achieve the necessary stability - in particular in landing-type aeroplane configurations - control surface forces are directed in the opposite direction to the lift developed by the aerofoil, that is, downwards. In other words ensuring the necessary stability results in the need to build larger aerofoil. A partial solution to the problem described above is the use of the tail-first design where the stabilizing force is generated in front of the aerofoil. Such a system, however, is connected with the presence of a few unfavourable phenomena which have caused this particular design to be withdrawn from wider use.
The flying craft control method provided by the present invention is characteristic in that an airframe with the required level of stability is added in the front section at a far distance from the centre of gravity of the airframe with an additional control surface where constant aerodynamic force is present irrespective of the angle of attack of the airframe, the control surface setting angle and other elements of the configuration of the airframe and which depends on the pilot's actions on control devices connected electrically and/or hydraulically to the additional control surface so that a given level of displacement of the control device results in a specified level of force being applied onto the additional control surface while that surface is suspended on a lateral axis located in front of the resultant aerodynamic forces acting on that surface while constant adjustable torque is applied to the axis which is set by the pilot or that the displacement of that surface is changed so that a difference in pressure that is constant and at the same time controlled by the pilot can be achieved in selected places of the top and bottom side of that surface.
An airframe equipped with an additional control surface is shown in the drawing where fig. 1 shows an end view of such an airframe and fig. 2 shows a top view of such an airframe.
As shown in the drawing an airframe 8 with the necessary level of stability is added in the front section clearly in front of the centre of gravity 4 of the airframe 8 with an additional control surface 1 where constant aerodynamic force 3 is present which is independent of the angle of attack of airframe 8, the control surface setting angle or other elements of the configuration of the airframe 8 but which is dependent on the will of the pilot acting though control devices in the form a control wheel or control stick that are connected electrically or hydraulically with the additional control surface 1 so that a given level of displacement of the control device results in a specified level of force being applied onto the additional control surface 1. In order to generate force on the additional control surface 1 located clearly in the front section in front of the centre of gravity 4 of the airframe 8 that is dependent on the will of the pilot but independent of the angle of attack of the flying craft, the angle of displacement of the control surface 1 and independent of other configurations of the airframe 8 the surface 1 is suspended on a lateral axis 2 located in front of the resultant of the aerodynamic forces 3 acting on that surface 1 while constant torque is applied to the axis 2, which may be changed by the pilot, for example, using an electric motor with constant torque whose torque depends on voltage control effected by the pilot. In order to generate force on the additional control surface 1 placed clearly in the front section in front of the centre of gravity 4 of the airframe 8 that is dependent on the will of the pilot but independent of the angle of attack of the flying craft, the angle of displacement of the control surface 1 and independent of other configurations of the airframe 8, the surface 1 is suspended on the lateral axis 2 and controlled through a servomechanism 7 in such a way that the displacement of that surface is changed so that a difference in pressure that is constant and at the same time controlled by the pilot can be achieved in selected places 5 of the top and bottom side of that surface and thanks to which constant force that is controlled by the pilot can be generated that will be used to control and balance the flying craft.
As shown in the drawing and as opposed to surfaces of this type used so far the surface according to the invention is controlled in such a way as to generate a precisely specified level of force that is controlled by the pilot. The force can be made to be dependent on the current angle of attack at which air is flowing around the aeroplane, the angle of displacement of the additional control surface, the speed of the aeroplane relative to the air, the current configuration of the aeroplane, that is on control unit, flap and undercarriage displacement and the location of the centre of gravity.
The idea of creating stability is mainly based on that a change in the angle of attack in an aeroplane and what follows from that on its control surfaces causes torque forces to appear that return the aeroplane to a state of equilibrium. For this reason the use of an additional surface generating force as described above does not cause a loss in system stability, however, it makes it possible to generate additional lift supporting the airframe, and what is most important it enables offsetting the unfavourable torque caused by flap or control unit displacement which result in negative force at the elevator unit. This task can be achieved by suspending the proposed additional surface on an axis placed in front of the point of application of the resultant aerodynamic force acting on it. Because of the relatively small working range of displacement of that surface it can be assumed that the requirement to have constant controllable force can be replaced with the requirement to have constant torque in relation to the axis of suspension of the additional surface. Constant torque independent of such factors as the angle of attack and which could be freely adjusted by the pilot can be achieved through the use of an electric motor in which torque depends on the voltage that is supplied. If the dynamic characteristics of the system turn out to be unfavourable a system must be then used in which a servomechanism moves the additional control surface so that a constant and specified difference in pressure is present between the top and bottom surfaces and thus constant and specified force acting on the surface.
In practical applications of the method according to the present invention it can be used as a balancing system, that is, a system where aeroplane control is effected using traditional control units while the additional control surface is used to achieve a desired state of equilibrium, that is, for example in order to generate additional lift at take-off or landing, offsetting flap displacement or to use it as the main control element of the aeroplane without the use of traditional control units, however, with stabilizing surfaces left and aeroplane control effected through changes in the force generated by the additional surface, which in this case will be possible thanks to the connection between the control surface and a control device and which would be assisted by the use of an electric or hydraulic system, for example, in such a way that a specified level of displacement of the control device corresponds to a specified level of force generated on the control surface. The ratio between those figures may be different depending on the type of the aeroplane, its size, use and its other technical parameters.
The above-mentioned cases describe how the aeroplane control method can be used mainly in the altitude control system of an aeroplane where changes affect the axis of rotation in the horizontal plane perpendicularly to the direction of flight. In certain cases, however, it may turn out that it would be desirable to use such a system also for directional control, which may mainly apply in the case of delta wing aeroplanes or aeroplanes with similar designs.
Patent claim
A flying craft control system characteristic in that an airframe with the necessary level of stability is added in the front section at a far distance in front of the centre of gravity (4) of the airframe (8) with an additional control surface (1) on which constant aerodynamic force is present which is independent of the angle of attack of the airframe, the control surface setting angle and other elements of the configuration of the airframe and which is dependent on the pilot's actions on an electrical and/or hydraulic connection between the additional control surface and control devices so that a given level of displacement of the control device corresponds to a specified level of force on the additional control surface while that surface is suspended on a lateral axis (2) located in front of the resultant aerodynamic forces (3) acting on that surface and while adjustable constant torque is applied to such an axis that is set by the pilot or where the displacement of that surface is changed so that a constant but pilot controllable difference in pressure can be achieved in selected places (5) on the top and bottom side of the surface.
Edward Margański
DESCRIPTION
FUSELAGE
CONTROL
SYSTEM
POWER
PLANT
TECHNICAL
DATA
NEW
CONCEPT IN
MILITARY PILOTS
TRAINING
PROGRESS
OF WORKS
DESCRIPTION
FUSELAGE
CONTROL
SYSTEM
POWER
PLANT
TECHNICAL
DATA
NEW
CONCEPT IN
MILITARY PILOTS
TRAINING
PROGRESS
OF WORKS
DESCRIPTION
FUSELAGE
CONTROL
SYSTEM
POWER
PLANT
TECHNICAL
DATA
NEW
CONCEPT IN
MILITARY PILOTS
TRAINING
PROGRESS
OF WORKS
DESCRIPTION
FUSELAGE
CONTROL
SYSTEM
POWER
PLANT
TECHNICAL
DATA
NEW
CONCEPT IN
MILITARY PILOTS
TRAINING
PROGRESS
OF WORKS
