104 results about "Center of gravity of an aircraft" patented technology

Fuel transference between aircraft fuel tanks, disposed in different locations, is used to maintain the aircraft Center of Gravity close to the aft limit of the certified Center of Gravity versus weight envelope. Continuous fuel transfer decreases the control band thus enhancing aircraft performance.

The aircraft is capable of two distinct fuel-efficient flight regimes: one is a vertical flight regime supported by two large two-bladed rotors with low disc loading located on right and left longitudinal booms. The booms extend between outboard regions of a front wing and inboard regions of a rear wing that has a larger span an area. The other flight regime is high speed up to high subsonic Mach number with the aircraft supported by wing lift with high wing loading, and with the rotors stopped and faired with minimal local drag contiguous to the booms. The longitudinal location of the aircrafts center of gravity, aerodynamic center and the center of the rotors are in close proximity. The front wing is preferably swept back, and the rear wing is preferably of W planform.

A method of controlling wing position and velocity for a flapping wing air vehicle provides six-degrees-of-freedom movement for the aircraft through a split-cycle constant-period frequency modulation with wing bias method that generates time-varying upstroke and downstroke wing position commands for wing planforms to produce nonharmonic wing flapping trajectories that generate non-zero, cycle averaged wing drag and alter the location of the cycle-averaged center of pressure of the wings relative to the center of gravity of the aircraft to cause horizontal translation forces, rolling moments and pitching moments of the aircraft.

An aircraft for transporting passengers and cargo able to efficiently handle ground operations for loading/unloading cargo and embarking/disembarking passengers at the same time. The lifting structure of the aircraft is formed by a back-swept wing and a fore-plane, the back-swept wing including winglets having a length L allowing them to act as vertical stabilizers. The propulsion system is mounted aft of the center of gravity of the aircraft and the tailcone of the fuselage is configured to act as a rear access door and as a pressure barrier.

Systems and methods for determining center of gravity for an aircraft. An example system includes one or more load measurement devices that generate one of nose gear or main gear weight information and a processing device that determines center of gravity of the aircraft based on previously received gross weight information and the generated nose or main gear weight information. The number of gear sets with load measurement devices is one less that the total number of gear sets having distinct longitudinal positions along a fuselage of the aircraft. The processing device further determines center of gravity based on temperature and/or pitch attitude information. The system includes a user interface that allows a user to enter the gross weight information that might be included in a flight manifest or a load and trim sheet and/or a communication component that receives the gross weight information from a ground-based system.

A system and method of calculating a center of gravity of an aircraft positions an aircraft on an aircraft scale. Weight readings are recorded at each wheel of the aircraft. A photograph of the aircraft on the aircraft scale is taken. The photograph is downloaded to a computer. Relative position readings between identifiable points on the photograph of the aircraft are taken. The relative position readings are transformed into an aircraft coordinates system. The weight readings taken at each wheel of the aircraft are then entered and the longitudinal center of gravity of the aircraft is calculated.

A method of controlling the centre of gravity of an aircraft having a plurality of fuel tanks, the method comprising transferring fuel from one or more of the fuel tanks according to a predetermined sequence, the timing of the sequence being dependent on the decrease in gross weight of the aircraft.

The invention discloses a side-by-side distribution-typed oil tank system, which is characterized in that: five oil tanks are sequentially distributed along the longitudinal direction of an airplane and are symmetrically distributed along a longitudinal axis and a transverse axis in an axon system adopting the gravity center of the airplane as an origin, two bubble-preventing oil tanks or counterweights are symmetrically distributed on the left side and the right side of the airplane, all oil tanks are sequentially connected with each other through connecting pieces and flexible rubber oil pipes according to a stipulated oil supply path, so the obvious variation of the position of the gravity center of the airplane with a flying swing layout caused by the consumption of the fuel oil can be overcome; and under the situation that the oil is non-uniformly absorbed because of stalling of one engine at one side of the airplane or asymmetric power of the engines at two sides of the airplane during flying, the position of the gravity center of the airplane can be maintained constant. In addition, the side-by-side distribution-typed oil tank system is simple to produce, has low cost and short period, is practical and reliable and is convenient to use, different fuel systems with different sizes can be produced according to a specific size of the airplane, and the side-by-side distribution-typed oil tank system is particularly suitable for the small-sized turbo-jet flying-swing layout unmanned proof airplane.

The invention discloses an airplane gravity center automatic regulation system, which comprises a center display control sub system and an antifreezing solution balancing sub system connected with the center display control sub system, wherein the center display control sub system comprises a control cabinet arranged in an airplane passenger cabin and a gravity center display touch screen arranged in a cab; an integral work station, a PLC (programmable logic controller) and an AD (analog-to-digital) conversion module are arranged in the control cabinet; the output end of the PLC is connected with the AD conversion module and is then connected with the integral work station. The invention also discloses a regulation method of the airplane gravity center automatic regulation system. The problem of large airplane gravity center position change range in the airplane flying process in the prior art is solved.

The invention relates to the aircraft weight measurement field, and in particular relates to an intelligent tester for weight and center of gravity of an aircraft. The intelligent tester for weight and center of gravity of the aircraft comprises a front airplane wheel electronic scale, a main airplane wheel electronic scale, a lifting platform, a laser ranging unit and a display control unit, the laser ranging unit sends the data to the display control unit, the display control unit sends the control signal to the lifting platform, the lifting platform can adjust the lifting degree for adjusting the airplane horizontally according to the signal sent by the display control unit, the display control unit collects the data of the front airplane wheel electronic scale, main airplane wheel electronic scale and the laser ranging unit for calculating and displaying the weight and center of gravity. The laser ranging unit is the laser range finder used for sending the height difference data and the level parallel data of the measuring points at the front, rear, left and right sides of the airplane to the display control unit. The intelligent tester for weight and center of gravity of the aircraft has beneficial effects: all problems can be solved, such as the measurement workload for the weight and center of gravity of the aircraft is too much, the weighting efficiency is low, the degree of accuracy is difficultly raised and the device applicability is not strong can be solved.

The invention relates to a helicopter weighing measurer and a helicopter gravity core measuring method. The helicopter weighing measurer comprises a shell and four spoke press-type sensors which are arranged in the shell, wherein a bearing column of each spoke press-type sensor is used for sensing the deformation of the stressed shell, the four spoke press-type sensors are connected with one another in parallel to form a force sensing assembly; the input end of the force sensing assembly is connected with a voltage stabilizing circuit, and the output end of the force sensing assembly is connected with a current amplifier; and an output impedance adjusting resistor is bridged between a first signal output end and a second signal output end of each spoke press-type sensor, and the first signal output end and the second signal output end of each spoke press-type sensor are respectively connected with an isolation resistor. The four spoke press-type sensors are connected in parallel, so that the measuring precision is improved.

Systems for propelling and controlling attitude of aircraft. Systems according to certain embodiments of the invention employ a fan whose rotational axis is preferably generally parallel to the yaw axis of the aircraft and which is preferably generally aligned with the center of gravity of the aircraft at least during the vertical phases of flight. Efflux from the fan can be routed downward through a vertical outlet for providing lift and vertical flight, and aft through a propulsion duct for providing thrust in horizontal flight modes. Vanes in the vertical outlet can be used to direct flow of efflux more in a forward or aft direction for “balancing” of the aircraft about the rotor in vertical flight. A vector unit located away from the center of gravity of the aircraft, such as in or near the tail of the aircraft, through which engine efflux can be routed, employs vanes to direct efflux flow, in a controllable fashion, upward, downward, port and/or starboard for commensurate control of the pitch and yaw of the aircraft.

The invention discloses an airplane gravity center envelope calculation method. The method comprises the steps that original parameters of an airplane are input, and the loading condition and the initial gravity center position are given; according to the aircraft aerodynamic model, the undercarriage model, the engine model and the full-aircraft flight mechanical model, calculating full-aircraft aerodynamic force and aerodynamic moment of the aircraft, and finishing trimming; the load weight and the gravity center position are dispersed; judging whether the aircraft can normally cruise and flyand normally take off and land or not; and then introducing static stability margin constraint and wing and horizontal tail limit load constraint under the condition of large aircraft load under thecondition of minimum horizontal flight speed to obtain a relation graph of front and rear gravity center limits and aircraft flight weight. According to the method, discretization processing is carried out on the load gravity center coordinate point, the flight process and the take-off and landing process of the aircraft are simulated, the gravity center of the aircraft is accurately calculated, the process is simple, and calculation is convenient.

The invention discloses a quasi-static undercarriage dynamics model construction method, and belongs to the technical field of aircraft simulation. The method includes: step 1, inputting aircraft state parameters, and internally constructing main undercarriage-system parameters; step 2, constructing a tire coordinate system, a half-wheel-axis coordinate system, a shock-absorbing pillar coordinate system and an aircraft body coordinate system, and establishing conversion matrices of mutual conversion of all the coordinate system; step 3, calculating whether aircraft wheels are in contact with ground and whether shock-absorbing pillars are compressed, and calculating corresponding tire pressure; step 4, using the iterative initial values to calculate stress of each shock-absorbing pillar, stress of each wheel axis and stress of each tire until difference values between two frames thereof meet a threshold value requirement; step 5, obtaining received resultant force and a resultant moment of a body axis system at a gravity center of the aircraft by solving through coordinate conversion; and step 6, outputting calculation process parameters according to needs. According to the method, a solving process of undercarriage system parameters is simplified while aircraft ground-motion simulation precision is guaranteed, running efficiency of a simulation program is improved, and dependence of the model parameters on flight test data is reduced.

A method and its control mechanics for manipulating the pitching of the miniature airplane feature that the relative position of the airplane's gravitation center to its pneumatic center on the axis of airplane body and the length of the force arm between pneumatic power and said gravitation center are changed by connecting wing and airplane body to become a parallelogram to generate additional pitching moment for manipulating airplane.

The invention discloses a configuration method for man-machine interactive airplane mission payload, and belongs to the field of airplane weight engineering. The configuration method comprises the following steps: configuring an oil consumption rule: selecting a corresponding oil consumption rule by aiming at different mission configurations; configuring effective payload: according to mission requirements, assigning an effective payload type for the specific position of the airplane; virtualizing fuel consumption: simulating the change of the weight, the center of gravity and the rotation inertia of the airplane in a fuel consumption process; virtualizing payload consumption: under the state of airplane assigned excess oil, simulating the change situation of the weight, the center of gravity and the rotation inertia during effective payload consumption (such as weapon put/emission). The configuration method has the advantages that the technical scheme can virtualize the payload put/emission on the basis of the center of gravity and the fuel consumption curve of the airplane to precisely calculate the weight, the center of gravity and the rotation inertia of the airplane in real time, and estimate the change range of the center of gravity of the airplane, and therefore, a problem that the change range of the center of gravity of the airplane only can be roughly estimated with a traditional means is solved.

The invention discloses a 360-degree omni-directional overload flight simulator. The center of gravity of a trainee is in the front of the center of the gravity of an airplane like in the real flight process. The 360-degree omni-directional overload flight simulator comprises a vertical lifting system, a first movement system, a second movement system and a flight cockpit system, wherein an intelligent control system has control over a front-and-rear pitching motor and a left-and-right rotating motor, the center of gravity of the trainee is in the front of the center of gravity of the airplane like in the real flight process, and the pilot can feel transverse movement and rotation at the same time; the intelligent control system converts various rotation overload motions of the vision into electric signals, and controls a stepping motor to synchronously move in the X direction, the Y direction and the Z direction. When the 360-degree omni-directional overload flight simulator is used, the training cost can be reduced, the training effect can be ensured, and the airplane driving training time of trainees such as trainee pilots can be shortened.

The invention provides a similar flying saucer type rotaplane, and relates to an unmanned aerial vehicle. The invention provides a similar flying saucer type rotor unmanned aerial vehicle which fully utilizes the self-stabilization effect of a top. The rotaplane is provided with a plane body, plane wings, two motors, a variable pitch system and variable pitch propellers, wherein the plane body is connected with the roots of the plane wings, and the inside space of the plane body is used for loading airborne equipment; the plane wings which adopt small short-edge oval wing shapes are used for realizing conversion among the vertical take-off and landing state, hovering state and cruise of fixed wings; the two motors are mounted on the positions of the wing tips of the plane wings on two sides, and the rotating directions of the two motors are consistent; the variable pitch system is used for regulating the propeller pitch of the variable pitch propellers; the variable pitch system is used for regulating the propeller pitch of the propellers to change the thrust direction and the thrust of the propellers, and the switchover between a hovering mode and a cruise mode is realized. The structure is simple, the sensitivity to the center of the gravity of an airplane is weak, and the overall aerodynamic efficiency is high.