Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
  • G09B9/00—Simulators for teaching or training purposes
  • G09B9/02—Simulators for teaching or training purposes for teaching control of vehicles or other craft
  • G09B9/08—Simulators for teaching or training purposes for teaching control of vehicles or other craft for teaching control of aircraft, e.g. Link trainer
  • G09B9/16—Ambient or aircraft conditions simulated or indicated by instrument or alarm
  • G09B9/165—Condition of cabin, cockpit or pilot's accessories

Definitions

• the invention relates to a method of boundary flight mode and overload simulation and device for performing of this method.
• the described simulation enables to model vibrations when stalling on wings and other aircraft parts occurs. Furthermore, it simulates vibrations during turbulences and variable vertical G-load.
• the k own simulation jechn ⁇ ques._ enable descent of an aircraft, its acceleration and deceleration, as well as vibrations and turbulences.
• Simulators have been used for this purpose enabling realistic simulation for pilots of high-capacity airliners and of helicopters. This device simulates banked flight and climbing and descent not exceeding 30°. However, unrealistic situations arise when high banks and higher than the 30° threshold climbing and descent are simulated. This applies first and foremost to vibrations, which do occur, but in frequencies and amplitude different from vibrations experienced during a real flight. The described situation results in incorrect habits of trained pilots.
• the existing vibration simulators are based on moving platforms with up to six degrees of freedom. A cockpit is mounted on top of such platform.
• the moving platform features include forward and backward cockpit tilting, banking during simulation of movements around aircraft longitudinal axis and up and down cockpit movements. Such moving platform may be used to simulate whether vibrations occur or not but it cannot replicate real-life values.
• a specially adapted simulator for training pilots to withstand a pre-defined G-load Such device includes various centrifuges enabling to train G-load in passive mode, however, without any possibility to train pilot for interactive flight.
• Every aircraft has its own vibration limit, which is achieved as soon as the aircraft flies above a certain stalling angle of attack. This may happen during high G-load, in flight at low speed or at high altitude.
• the higher the angle of attack over a stalling AOA the higher the vibration amplitude and, to certain extent, also the vibration frequency.
• Pilot controls aerobatics intuitively according to the two above-mentioned criteria. When s/he is unable to watch instruments due to other important tasks, or because it is not necessary, s/he tries to fly at vibration limit. Pilot may also follow his/her feeling according to G-load. It is frequently the pressure on pilot's body G-suit that serves him/her as a guideline.
• Aircraft G-load and angle of attack increase in sharp yawning in any direction of both real and simulated aircraft and pilot feels increased G-suit squeezing on his/her own body.
• cockpit starts to vibrate thus forcing pilot to diminish the vigorousness of manoeuvring, subsequently decreasing G-load and attenuating vibrations.
• Same conditions must be met also during simulation since the majority of pilots trained on existing simulators fly aerobics and air manoeuvring very roughly and unrealistically. This is caused by insufficient information about vibrations from inside of cockpit during training. Even though every pilot gets such feedback in a real aircraft, none of the known simulators provides it. There exists no combined flight simulator equipped with both vibration platform and with G-suit provided with overpressure.
• the above-described issue is fixed by simulation device enabling to replicate both G- load and critical aerodynamic modes.
• the invention is based on continuous transmission of flight data from the simulated aircraft controls to central computer.
• This computer evaluates the received flight data. As soon as the received values correspond to a G-load the computer sends signals to squeeze the G-suit with same pressure as that experienced in real aircraft under the same G-load conditions. If the computer detects that the limit values of aerodynamic modes has been reached, above which vibrations occur, it sends appropriate signals to generate vibrations with the same frequency and amplitude as in a real flight at stalling which results from exceeded boundary modes.
• the appropriate device includes a cockpit mounted on a vibration platform. The cockpit is equipped with controls of simulated aircraft, together with a pilot's seat.
• the invention principle consists of vibration platform composed of a swinging frame with a hydraulic cylinder connected to its rear part.
• the rear hydraulic cylinder is coupled with rear hydraulic source through rear pressure piping.
• Pressure air accumulator is connected to cockpit inlet through air valve and upper pressure piping.
• Pressure air accumulator is feeded by compressor.
• Combined output from controls of the simulated aircraft couples with combined input to control computer, combined output of which leads to both control input of air valve and control input of rear hydraulic source.
• Swinging frame front sits on fixed frame through pivot joint.
• the invention offers beneficial layout, which enables to set up cockpit environment that simulates to the maximum extent real conditions and feelings pilot experiences even during aerobatics. It enables partial simulation of aircraft movements of the ground (e.g. landing gear jumping and impacts on seams of a concrete runway). It even makes it possible to imitate aircraft vibrations that occur when aircraft approaches stalling speed and in any other combination of speed, angle of attack, height and atmosphere density. Squeezing of G-suit, which trained pilot wears, simulates aircraft G-load. Vibration simulation combined with G-load simulation by modifying pressure in G-suit offers high fidelity feelings experienced in manoeuvring during flight. Furthermore, this results in high quality of acquired aircraft/helicopter manoeuvring habits. Joint employment of the described invention, together with ground simulator equipped with large display screen, considerably enhances the quality of aircraft control close to that of aerobatics in real aircraft. Results of this method are substantially better than those of known simulation methods on simulators with moving platform.
• Figure 1 shows device with cockpit mounted on a moving frame, which is connected to a fixed frame through front pivot joint, while the rear part of the swinging frame couples with rear hydraulic cylinder.
• Figure 2 describes the modification where cockpit is mounted on a swinging frame connected on its rear part with rear hydraulic cylinder and on its front part with front hydraulic cylinder.
• Method of boundary flight mode and overload simulation and of critical aerodynamic modes is based on continuous flight data transfer from simulated aircraft controls to control computer where data is analysed. As soon as the analysis results reveal that a situation has arisen, when G-load occurs, the computer sends signals to squeeze G- suit. Pilot thus experiences the same feeling as in a real aircraft under the same G-load. As soon as the computer analysis of flight data from simulated aircraft shows that the simulated aircraft has reached limit conditions, when vibrations start, it sends signals to generate appropriate vibrations. Vibration frequency and amplitude is equal to those experienced in real aircraft flying under the same stalling conditions.
• the simulation device imitating limit aerodynamic modes consist of a vibration platform made by swinging frame 2 on which cockpit 4 is mounted.
• the cockpit 4 has inlet 7 that is coupled through upper pressure piping 12 and air valve 9 with pressure air accumulator 11
• the volume of the accumulator H is at least 1 cubic metre and it is connected to low-pressure compressor 10 .maximum pressure 20 hPa with automatic pressure control.
• the rear part of the swinging frame 2 is coupled with rear hydraulic cylinder 5 that is connected to rear hydraulic source 6 through rear pressure piping 8.
• Control computer 20 generates simulation of vibrations, corresponding to limit flight modes, and of G-load on the base of signals received from simulated aircraft controls 2 ⁇ located in cockpit 4. Simulated aircraft controls 2 ⁇ combined output 21.1 is connected to the control computer 20 combined input 20.1.
• Combined control output 20.2 leads to air valve , 9 control input 9 . and to the rear hydraulic source 6 control input 6 ..
• the alternative illustrated on figure 1 has the front part of swinging frame 2 mounted through pivot joint 3 on fix frame . The latter is fixed to the floor.
• the modification illustrated on figure 2 has the swinging frame 2 front part connected to second hydraulic cylinder 50, which is, on its turn, connected to a second hydraulic source 60.
• Control input 60.1 of the second hydraulic source 60 is connected to control computer 2 combined output 20.2. Shaking of the swinging frame 2 provides cockpit 4 vibrations in limit modes of aircraft stalling.
• Rear hydraulic cylinder 5 takes care of simulated vibrations in layout depicted on figure 1 , where cockpit 4 is mounted on a swinging frame 2, which, on its turn, sits on pivot joint 3 connecting it to the fixed frame 1 Hydraulic cylinder 5 allows vertical movements of the swinging frame 2 up to
• Signals from individual flight data of aircraft controlled by trained pilot are conducted through aircraft controls 2 combined output 21.1 to the control computer 20 combined input 20.1.
• the control computer 20 analyses the data and generates signals with frequency and amplitude equal to those of a real aircraft under the same conditions when the flight mode corresponds to a limit situation.
• Generated signals are sent through the control computer 20 combined output 20.2 to both the rear hydraulic source 6 control input 6 . and to the front hydraulic source 60 control input 60.1. Signals of corresponding frequency and amplitude control the hydraulic control valve, not depicted on figures. The latter allows appropriate volume of hydraulic liquid to flow from the hydraulic source 6 into the hydraulic circuit. Appropriate pressure signals are thus generated both in the rear 6 apd front 60 hydraulic sources.
• Hydraulic signals from the rear hydraulic source 6 are transferred via the rear pressure piping 8 to the rear hydraulic cylinder 5. Hydraulic signals from the front hydraulic source 60 are transferred via the front pressure piping 13 to the front hydraulic cylinder
• Both the rear 5 and the front 50 hydraulic cylinders generate vibrations with frequency and amplitude equal to those occurring in real flight under the same conditions.
• This device generates vibrations of amplitude ⁇ 30 mm and frequency of up to 15 Hz. Amplitude and frequency of strokes is electronically controlled. The data is adjusted to particular aircraft type for control of which pilot trains.
• the control computer
• control computer 20 generates also vertical G-load, which level is based on analysis of the received signals. These signals come from simulated aircraft controls 2J_ combined output 21.1 and are conducted to the combined input 20.1 of control computer 20. If the analysis of control signals reveals that pilot entered a mode when vertical G-load occurs the control computer 20 sends signals via its combined output 20.2 to the air valve 9 control input
• the value of signals corresponds to the level of G-load.
• the air valve 9 In case of zero G-load the air valve 9 is closed.
• the air valve 9 opens or closes according to increase or decrease of vertical G-load, thus enabling higher or lower air pressure to flow from pressure air accumulator V ⁇ _ to the upper pressure piping 12, which is terminated by inlet 7. This inlet
• G-suit 7 is connected with a G-suit or G-trousers, which make part of pilot's device (not illustrated).
• G-suit or G-trousers which make part of pilot's device (not illustrated).
• the device is, in the majority of cases, used to simulate vibrations occurring when limit aircraft mode is achieved, together with G-load simulation. However, it may be used to simulate just on of the two modes, limit vibrations or G-load. In such case, the device works as two independent simulators, each of them simulating the selected function alone.
• the invention will be used to train pilots of both sports planes and fighters, first and foremost to train aerobics and advanced manoeuvring, . , . . foi

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• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Business, Economics & Management (AREA)
• Physics & Mathematics (AREA)
• Educational Administration (AREA)
• Educational Technology (AREA)
• General Physics & Mathematics (AREA)
• Management, Administration, Business Operations System, And Electronic Commerce (AREA)

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• 2000
  • 2000-09-26 CZ CZ20003546A patent/CZ291056B6/cs not_active IP Right Cessation
• 2001
  • 2001-09-25 WO PCT/CZ2001/000055 patent/WO2002027695A2/en active Application Filing

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