Abstract:
The invention relates to a flight simulator vibration system, particularly to a crew seat ( 1 ), a flight control stick ( 20 ) and a panel ( 30 ) vibration system of a flight simulator with at least one plate of the crew seat ( 1 ), the flight control stick ( 20 ) and/or the panel ( 30 ) being equipped with predefined momentum weights ( 13, 16 ) and electric motors driving said respective momentum weights. Speed governors are controlling individually said electric motors ( 7, 8, 9, 21, 33, 34 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of EP 10 400 020.3 filed on Mar. 29, 2010, the disclosure of which is incorporated in its entirety by reference herein. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field Of The Invention 
         [0003]    The invention relates to a flight simulator vibration system, particularly to a crew seat, a flight control stick and a panel vibration system of a flight simulator with the features of the preamble of claim  1 . 
         [0004]    2. Description Of Related Art 
         [0005]    The design of a low-cost simulation system to replicate helicopter/shipboard launch and recovery envelopes reduces the reliance on expensive at-sea developmental flight tests. A high-frequency, low-amplitude motion with a three degree of freedom (3DOF) seat shaker / motion system allows simulator systems integrators to provide motion and vibration cues to an operator without the expense of a full cab motion system providing pitch, roll and heave cues to the operator&#39;s seat based on the simulated vehicle&#39;s motion. Vehicle X and Y cues are also blended into the motion to provide realistic driving cues. Vibrations of 10 Hz until 40 Hz, with a preferred value of 25 to 26 Hz, depending on the vibrations simulated, can be provided to each of the three degrees of freedom. The seat motion system control electronics are packaged as a self-contained simulation node that performs the required cueing algorithms locally at a high iteration rate and can communicate with other simulation components over serial or Ethernet connections. The node receives vehicle state information from the vehicle dynamics model as well as vibration and discrete bump commands. 
         [0006]    For flight simulation it is known to use motion simulators including 6-post motion platforms with the platform being supported by 6 active hydraulic actuators. The 6-post is essentially a hydraulic position servo driven by commanded leg or actuator lengths computed by a motion system mathematical model. 
         [0007]    Seat shakers of the state of the art are different from the original seat and very expensive. Their control is affected via complicated software and necessitates interference with existing system components. Some of the vibrations created by the seat shakers of the state of the art are likely to deteriorate the operation of adjacent systems. 
         [0008]    U.S. 2009154737 A1 discloses an apparatus, system and method for an entertainment chair to provide a high fidelity audio system incorporated in an entertainment chair. The entertainment chair is relatively independent from an acoustical environment in which it is placed and enables repeatable high fidelity sound with a wide variety of recording types and qualities. A subwoofer is placed in the backrest and a shaker is placed in the seat bottom. The subwoofer and shaker are separately tuneable through a control panel ergonomically placed at a forward end of an arm rest. The control panel includes a universal iPod dock. Other inputs may also be connected to the entertainment chair. This system is dedicated to personal entertainment and is not suitable for any flight simulation. 
       SUMMARY OF THE INVENTION 
       [0009]    It is an object of the present invention to provide a flight simulator vibration system, particularly a crew seat, a flight control stick and a panel vibration system of a flight simulator without the disadvantages of the state of the art and improving the feeling of a pilot or a crew in order to present an utmost realistic flight simulation. 
         [0010]    The solution is provided with a flight simulator vibration system, particularly a crew seat, a flight control stick and a panel vibration system of a flight simulator with the features of claim  1 . Preferred embodiments of the invention are provided in the sub claims. 
         [0011]    According to the invention a flight simulator vibration system is provided with at least one crew seat, at least one flight control stick and at least one panel vibration system comprising each predefined momentum weights and electric motors driving said respective momentum weights and at least one speed governor controlling preferably individually said electric motors. The invention provides the advantages of a complete and modular flight simulator vibration system. 
         [0012]    According to a preferred embodiment of the invention a flight simulator crew seat comprises at least one supplemental plate integrated into the seat with predefined momentum weights and three electric motors for each plate driving said respective momentum weights. An electronic control circuit is provided particularly conceived as speed governor controlling said three electric motors in order to provide different frequencies of oscillation and orientation to the momentum weights in the direction of all three coordinate axis. It is one advantage of the present invention to provide a flight simulator crew seat vibration system improving the feeling of a pilot or a crew for an utmost realistic flight simulation. The inventive flight simulator crew seat supplies the means to avoid the so called simulator sickness. The seat of the invention is built up from an original crew seat and thus looks the same and feels the same as an original seat and provides for a genuine flight feeling and reflection of the real oscillations of an aircraft. The flight simulator crew seat of the invention may be used in a full flight simulator (FFS) after certification and approval from the authorities in charge. The inventive flight simulator crew seat can be built up from all original crew seats and without extra time consumption. Considerable savings in costs may be achieved with the inventive system as deficient systems through oscillation damages can be avoided. The inventive system is less bulky and leads to less weight than with a flight simulator crew seat according to the state of the art. The inventive system can be extended to customized solutions. According to the invention the control is driven by low voltage current in the range of up to 14 V thus avoiding any risks from the electric supply of the electro-motors to any users. According to the invention the electronic control circuit is independent without any need any to intercept into any existing systems for installation of the inventive flight simulator vibration system. Advantageously said control may be tuned according to the frequencies of sounds created in a simulation independent of any existing computer system with the frequencies of sounds created in the simulation corresponding preferably to the frequencies of a turbine, rotor or tail rotor of a helicopter. 
         [0013]    According to a further aspect of the invention the electronic control circuit is invisibly arranged outside the seat for improved modularity and better acceptance by the clients. The inventive seat may be fully adjustable with no restrictions from the inventive system. 
         [0014]    According to a further preferred embodiment of the invention the at least one supplemental plate is mounted to a backrest of the crew seat for transfer of its simulated vibrations directly to the back of the user in the seat. 
         [0015]    According to a further preferred embodiment of the invention at least one further supplemental plate is mounted to a sitting support of the crew seat for transfer of its simulated vibrations directly to the legs and body of the user in the seat. 
         [0016]    According to a further preferred embodiment of the invention each supplemental plate is provided with three electric motors each driving respectively one momentum weight for common control features of the simulated vibrations in separate plates. 
         [0017]    According to a further preferred embodiment of the invention flexible stripes are provided being arranged across casings of the electro-motors and screwed at their respective ends to the plate for economic and versatile installation of the electro-motors allowing easy rotation of the electro-motors. The technical effect is that by turning the motor casing the force direction is adjusted. 
         [0018]    According to a further preferred embodiment of the invention at least one control processor is provided and a DC pulse transformer as an interface to the electronic control circuit for filtering and preparation of the data for the control of the electro-motors. 
         [0019]    According to a further preferred embodiment of the invention microphones are provided, data from the microphones are filtered by the audio-frequency splitter and converted inside the control processor in order to allow simulation of vibrations corresponding to operational sounds, such as the sound from a rotor of an operating helicopter. 
         [0020]    According to a further preferred embodiment of the invention at least one external device is provided for transmittal of analog input data reflecting speed and/or flying position data (attitude) and/or digital input reflecting critical levels of flying position like a maximum bank angle. The analog and/or digital input goes directly to the electronic control circuit to allow integration of complex influences to the simulation of vibrations. 
         [0021]    According to another preferred embodiment of the invention a flight control stick vibration system is provided with an electro-motor with a momentum weight mounted eccentrically inside a security casing integral with the electro-motor allowing essentially modulated simulation of vibration in the flight control stick with the features of the vibration system of the at least one crew seat. 
         [0022]    According to another preferred embodiment of the invention a panel vibration system with at least one glare-shield is provided, said panel being provided with two electro-motors with respective momentum weights allowing reproduction of vibrations in said glare-shield with essentially the features of the vibration system of the at least one crew seat and/or the flight control stick. 
         [0023]    According to a preferred embodiment of the invention the momentum weights are adjustable and/or can be replaced for simple and versatile adaption of the flight simulator vibration system to a wide range of different samples. 
         [0024]    According to a preferred embodiment of the invention the electro-motors can be rotated for simple and effective tuning of the simulated vibrations. The technical effect is that it allows the force direction to change. 
         [0025]    According to a preferred embodiment of the invention the respective momentum weights and their respective orientations are calibrated for a start sample and consequent proceedings. 
         [0026]    According to a preferred embodiment of the invention three electronic control circuits are provided for shared processing with a back-up option and with at least one of said electronic control circuits being conceived as speed governor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    A preferred embodiment of the invention will be described by way of the attached drawings. 
           [0028]      FIG. 1  shows a view from behind onto a crew seat of a flight simulator vibration system according to the invention, 
           [0029]      FIG. 2  shows a schematic view of a part of a seat of said flight simulator vibration system according to the invention, 
           [0030]      FIG. 3  shows a schematic view of a lower plate of a seat of said flight simulator vibration system according to the invention, 
           [0031]      FIG. 4  shows a schematic view of an electro motor of said flight simulator vibration system according to the invention, 
           [0032]      FIG. 5  shows a schematic view of a flight control stick of said flight simulator vibration system according to the invention, and 
           [0033]      FIG. 6  shows a schematic view of a panel vibration system of said flight simulator vibration system according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]      FIG. 1 : A flight simulator vibration system for an aircraft and particularly for a helicopter, has as a basis a fully adjustable standard crew seat  1  of a helicopter (not shown) with all the features of a genuine crew seat particularly a cover  2  that can be opened and closed via a zip along a vertical direction of the backrest  3  of this crew seat  1 . 
         [0035]    An essentially rectangular plate  4  is mounted as a supplemental essentially parallel to the backrest  3  of this crew seat  1 . The plate  4  is made of aluminium with a 3-4 mm thickness and is fixed to a frame of the backrest  3  of crew seat  1  by way of screws and clamps  5 . 
         [0036]    Three independent, flexible stripes  6  are arranged across casings of electro-motors  7 ,  8 ,  9  and are screwed at their respective ends to the plate  4  to hold down the three casings of the electro-motors  7 ,  8 ,  9  against the plate  4 . The three electro-motors  7 ,  8 ,  9  are mounted to the plate  4  from the side opposed to the pilot&#39;s back. Two electro-motors  8 ,  9  are mounted to an upper part of the plate  4  and one electro-motor  7  is mounted to a lower part of the plate  4  with the electro-motors  7 ,  8 ,  9  having about the same distances between each other. Each of the flexible stripes  6  can be loosened individually by unscrewing at least one of their respective ends allowing the electro-motors  7 ,  8 ,  9  to be rotated individually in the plane of the plate  4  and relative to each other. This allows the force direction to be adjusted. 
         [0037]      FIG. 2 ,  3 ,  4 : Corresponding features are numbered with the same references as in  FIG. 1 . Flight operation data may be processed for genuine flight simulations. Audio data with real flight manoeuvre sound track may be recorded by microphones  10  transmitting frequencies to a control processor  11  for the electro-motors  7 ,  8 ,  9 . The frequencies from the microphones input  10  are filtered and processed in the control processor  11  via a DC pulse transformer (not shown) to control parameters, i.e. by partitioning the supply voltage for the respective electro-motors  7 ,  8 ,  9 . The control processor  11  is linked via a sub D interface to an electronic control circuit  12  and from there via shielded cables to the electro-motors   7 ,  8 ,  9 . Analog input with data of speed and/or flying position and digital input with data of speed limits and/or critical levels of flying position like a maximum bank angle may be fed directly to the electronic control circuit  12  from an external device  14 . The electronic control circuit  12  is conceived as speed governor for the electro-motors  7 ,  8 ,  9 . The electric power supply for the electro-motors  7 ,  8 ,  9  is based on 12-14 Volt transformed from the generally available 220 V (in the USA 110 V). 
         [0038]    An essentially rectangular lower plate  4   a  is integrated as a supplemental seat shaker into a sitting support of a flight simulator crew seat  1 . The lower plate  4   a  as well as electro-motors and the assembly of the lower plate  4   a  with the electro-motors correspond principally to the essentially rectangular plate  4  mounted as a supplement to the backrest  3  of this crew seat  1  of the flight simulator vibration system. The control and supply of the electro-motors of the lower plate  4   a  corresponds to the control and supply of the electro-motors  7 ,  8 ,  9  of the plate  4  at the backrest  3  of the crew seat  1 . Rubber dampers  17  are provided at each of the corners of the lower plate  4   a  for attenuating the impact of the vibrations from the lower plate  4   a  to the crew seat  1  of the flight simulator vibration system. 
         [0039]    The electro-motors  7 ,  8 ,  9  can be tuned individually up to 3000 RPM depending from the input from the electronic control circuits  12 . Each of the electro-motors  7 ,  8 ,  9  comprises a power shaft  15  to which a momentum weight  13  is mounted eccentrically inside a security casing  17  integral with the electro-motors  7 ,  8 ,  9 . The momentum weights  13  are rotating masses between 0,4 g to 400 g individually orientated to provide for different frequencies and orientations of the vibrations. Eccentricity of the respective momentum weights  13  may be adjustable by extra momentum weights  16  (s.  FIG. 4 ) that can be displaced radially with regard to the axis of the power shaft  15 . The security casing  17  is provided with an access to allow replacement and/or adjustment of the momentum weights  13 ,  16 . The orientation of the momentum weights  13 ,  16  can be tuned by rotating the electro-motors  7 ,  8 ,  9  individually or relative to each other under the loosened stripes  6  parallel to the plane of the plate  4 . At least one of a pair of adjacent electro-motors  7 ,  8 ,  9  is rotating anti-clockwise while the other one is rotating clockwise. 
         [0040]    The respective momentum weights  13 ,  16  and their respective orientations are first calibrated to correspond best to measurements of an operating aircraft to be simulated (not shown). For this end the amplitudes and frequencies of vibrations during operation of an aircraft are measured and registered and the registered data are transferred to the crew seat  1  of the flight simulator vibration system. The speed controllers  12  may be adapted to the registered measures to tune the rotational speed of the electro-motors  7 ,  8 ,  9  till the amplitudes and frequencies of the vibrations at the crew seat  1  of the flight simulator vibration system correspond to the registered measures. A profile from a plurality of registered measures can be created and stored in a memory to provide simulation of ongoing flight operations to the electro-motors. A helicopter main rotor at approximately 390 RPM and with 4 blades provides vibrations at frequencies of approximately 25/26 Hz. Thus for such a case vibrations resulting from the frequencies at 25/26 Hz have to be simulated in the crew seat  1 . 
         [0041]      FIG. 5 : Corresponding features are numbered with the same references as in  FIGS. 1 to 4 . A flight control stick  20  of a flight simulator vibration system is provided with an electro-motor  21  with a momentum weight mounted eccentrically inside an integral security casing alike any of the electro-motors  7 ,  8 ,  9 . A clamp  22  around the electro-motor  21  with the security casing is screwed to the flight control stick  20  next to the joints  23  linking the flight control stick  20  to the flight simulator vibration system. 
         [0042]    The electro-motor  21  is connected to the electric power supply via a power cable and to the electronic control circuit  12  via shielded cables  24 . 
         [0043]      FIG. 6 : Corresponding features are numbered with the same references as in  FIGS. 1 to 5 . A panel  30  of a flight simulator vibration system is equipped with a glare-shield  31 , such glare-shield  31  being supposed to avoid blinding of the instruments  32  by sunshine and thus obstructing the pilot&#39;s view in flight operation. The panel  30  is provided with two electro-motors  33 ,  34  with respective momentum weights allowing reproduction of vibrations of 4 Rev in the glare-shield corresponding to vibrations during genuine flight operation at a speed of ˜17 and 24 kts. The electro-motors  33 ,  34  of the panel  30  are alike any of the electro-motors  7 ,  8 ,  9  and are controlled by the electronic control circuits  12  for the crew seat  1  of the flight simulator vibration system.