Abstract:
An aircraft crosswind training simulator has a fixed-pitch cockpit rotatably mounted atop a platform. Rotation of the cockpit is controlled by motor controllers that are responsive to movement of the cockpit&#39;s steering control. A rotation sensor detects rotation of the cockpit and communicates with a motor controller that controls the direction and speed of a motor mounted to the platform. The motor is engaged with a drive wheel that drives the platform laterally across the floor in response to rotation of the cockpit that is detected by the rotation sensor. An instructor input switch manipulates the motor controllers to introduce additional forces to the rotation of the cockpit and/or additional forces to the lateral movement of the platform, simulating external forces present during crosswind conditions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/793,005, filed Apr. 18, 2006, which application is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates generally to aviation and, more particularly, to aircraft training simulators. 
     BACKGROUND OF THE INVENTION 
     Landing aircraft during crosswind weather conditions is one of the most demanding flight maneuvers in aviation flight, and is often difficult to learn due to the unique and assertive use of flight controls needed to be successful and safe during such landings. The National Transportation Safety Board (NTSB) cites crosswinds and gusts as the top two causes of weather related aircraft accidents, and about 90% of these accidents occur at wind speeds well below aircraft capability. This suggests that pilot skill is the primary shortfall. Despite the relatively high risk of accident during such maneuvers, many general aviation pilots receive limited training time in practicing landing aircraft during crosswind landing conditions, and as a result, often avoid attempting the maneuver, leading to degraded skills and increased apprehension that causes some to stop piloting altogether. 
     To provide meaningful crosswind landing training to pilots, aircraft training simulators should ideally duplicate conditions present in aircraft just prior to touchdown on the runway, such as forces exerted on the pilot&#39;s body, partially obstructed view of the runway, and peripheral vision cues necessary to make a proper landing. Most aircraft training simulators available at local airports, however, are stationary computer-based simulators that don&#39;t duplicate these conditions and are of little value for crosswind landing training. A few high-end computer-based training simulators do provide adequate crosswind landing conditions simulation, but do so with visual cues by moving images displayed on the simulator&#39;s computer screen to replicate conditions. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention involves providing an aircraft crosswind training simulator for teaching pilots to pilot and land aircraft during crosswind conditions. The aircraft crosswind training simulator has a fixed-pitch cockpit rotatably mounted atop a platform. Rotation of the cockpit is controlled by motor controllers that are responsive to movement of the cockpit&#39;s steering control. A rotation sensor detects rotation of the cockpit and communicates with a motor controller that controls the direction and speed of a motor mounted to the platform. The motor is engaged with a drive wheel that drives the platform laterally across the floor in response to rotation of the cockpit that is detected by the rotation sensor. An instructor input switch manipulates the motor controllers to introduce additional forces to the rotation of the cockpit and/or additional forces to the lateral movement of the platform, simulating external forces present during crosswind conditions. 
     The objects and advantages of the present invention will be more apparent upon reading the following detailed description in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the preferred embodiment of an aircraft crosswind training simulator according to one aspect of the present invention. 
         FIG. 2  is a front end view of the aircraft crosswind training simulator of  FIG. 1 . 
         FIG. 3  is an overhead view of the aircraft crosswind training simulator of  FIG. 1 . 
         FIG. 4  is a left side view of the aircraft crosswind training simulator of  FIG. 1 . 
         FIG. 5  shows detail of the front left corner of the aircraft crosswind training simulator of  FIG. 1 . 
         FIG. 6  shows detail of the roll motor drivetrain of the aircraft crosswind training simulator of  FIG. 1 . 
         FIG. 7  shows detail of the yaw motor drivetrain of the aircraft crosswind training simulator of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     One aspect of the present invention involves providing an aircraft crosswind training simulator  1  ( FIG. 1 ) for teaching pilots to pilot and land aircraft during crosswind conditions that duplicates conditions present in an aircraft just prior to touching down on a runway. 
     Referencing  FIG. 1 , the cockpit  10  of the simulator is designed to emulate the flight deck of a standard light aircraft. It supports seat  12  in which a student pilot is secured via a seat belt system. The student is seated in front of steering control yoke  14  and rudder pedals  16  which are situated for access similar to a standard light aircraft. The cockpit cowling  18  restricts the student&#39;s visual field and provides visual feedback similar to the cockpit of an actual airplane. While looking over the cowling  18 , the student sees a replicated aircraft runway centerline  20  on the floor in front of the cockpit. The combination of the centerline  20  and cowling  18  provide the primary visual feedback similar to that found in an actual airplane. 
     At the front and rear of cockpit  10 , roll pins  22  ( FIGS. 1 ,  3 , and  4 ) rest in roll bearings  24  that are attached to yaw fork  26  ( FIGS. 2 and 4 ), which fixes the pitch axis of the cockpit. Roll pins  22  provide the longitudinal axis (roll axis) about which cockpit  10  rolls when roll rotation of the cockpit it initiated. 
     The cockpit  10  is rolled left and right about its roll axis via force applied by roll motor  28  ( FIGS. 2 and 6 ) through the roll drivetrain. Roll motor  28  is preferably a reversing, variable speed ½ horsepower three-phase AC electric motor (synchronous or stepper-type, for example) with a combined gearbox that achieves the speed reduction necessary to provide acceptable low and high speed roll rotation rates by utilizing minimum and maximum drive frequencies of about 5 Hz to 90 Hz. Roll motor  28  is preferably controlled by a motor controller (control means)(not shown), such as an adjustable-speed drive (preferably a variable-frequency drive (VFD) type adjustable-speed drive), that determines the phasing and frequency of the power to the motor in order to control its direction and speed. 
     The on-board computer (not shown) calculates the desired roll motor speed and direction and then preferably provides an appropriate 0 to 10 VDC analog signal to the controller to indicate motor speed and direction in one signal. For example, a control scheme may comprise sending a 5VDC signal to the controller when a cockpit roll rotation speed of zero is desired, stopping motor  28 . 0 and 10 VDC signals, respectively, may then indicate desired cockpit rotation in opposite directions at maximum speeds, while in between values may represent linear changes in speed. Roll motor speed and direction is computed by algorithms that process information such as yoke position, rudder position, induced roll, and introduced wind condition forces, to produce desired effects that duplicate conditions in a light aircraft near landing speed with a pilot at the controls. 
     Roll motor  28  is attached to yaw fork  26 , and adjusts the cockpit roll rotation angle via the roll belt  30  and roll radius  32 . Roll belt  30  is a double sided synchronous belt affixed to the roll radius on one end through roll belt clamp  34 . Roll belt  30  rides the face of the roll radius  32  until it reaches roll guide pulley  36 , where it is directed around roll motor drive pulley  38  and back to opposing roll guide pulley  40 . Roll belt  30  again joins the roll radius  32  and terminates at roll belt tension clamp  42 . Roll belt tension clamp  42  can be adjusted to maintain correct belt tension on all roll drivetrain components. 
     Roll guide pulley  36  is supported by roll guide pulley shaft  44  ( FIG. 6 ), which is supported by roll guide bearings  46  and  48 . Opposing roll guide pulley  40  is supported by opposing roll guide pulley shaft  50 , which is supported by opposing roll guide bearings  52  and  54 . Roll guide pulleys  36  and  40  route roll belt  30  to roll motor drive pulley  38  and force roll belt  30  against roll radius  32 . Roll guide pulley shaft  50  also drives rotation sensor  56 , providing roll position input to the computer. Rotational movement of cockpit  10  is restricted by limit switches (not shown) through the computer controls and by way of mechanical stops (not shown) in case of control system failure. Rotation sensor  56  is generally a means for sensing rotation of the cockpit about its roll axis. The rotation sensor shown in the figures is a multi-turn potentiometer, but other rotary transformers (reslovers, rotary encoders, synchros) may also be used. 
     Yaw fork  26  ( FIGS. 2 and 4 ) supports cockpit  10 , roll motor  28 , step  58  and yaw radius  60 . Yaw radius  60  is similar to the roll drive radius  32  previously described. Yaw fork  26  is supported entirely on yaw bearing  62  ( FIG. 2 ) which allows yaw fork  26 , and thus cockpit  10 , to rotate about its vertical (yaw) axis. Its rotation is limited by limit switches (not shown) and by mechanical stops (not shown), in case of a control system failure. 
     Referencing  FIGS. 4 and 7 , yaw fork  26  rotates left and right via force applied by yaw motor  64  through the yaw drivetrain. Yaw motor  64  is preferably a reversing, variable speed ½ horsepower three-phase AC electric motor, similar to the roll motor described above. Yaw motor  64  is preferably controlled by a motor controller (not shown), such as a VFD, that determines the phasing and frequency of the power to the motor in order to control its direction and speed. 
     The on-board computer calculates the desired yaw motor speed and direction and then preferably provides an appropriate signal to the controller to control it in a manner similar to the roll motor control scheme example described above. Yaw motor speed and direction is computed by algorithms that process information such as yoke position, rudder position, adverse yaw, and introduced wind condition forces, to produce desired effects that duplicate conditions in a light aircraft near landing speed with a pilot at the controls. 
     Yaw motor  64  is attached to platform  66 , and adjusts the yaw rotation angle of the cockpit via the yaw belt  68  and yaw radius  60 . Yaw belt  68  is a double sided synchronous belt affixed to yaw radius  60  on one end through yaw belt clamp  70 . The yaw belt  68  rides the face of yaw radius  60  until it reaches yaw guide pulley  72  where it is directed around yaw motor drive pulley  74  and back to opposing yaw guide pulley  76 . Yaw belt  68  again joins yaw radius  60  and terminates at yaw belt tension clamp  78 . Yaw belt tension clamp  78  can be adjusted to maintain the correct belt tension on all yaw drivetrain components. 
     Yaw guide pulley  72  is supported by yaw guide pulley shaft  80 , which is supported by yaw guide bearings  82  and  84 . Opposing yaw guide pulley  76  is supported by opposing yaw guide pulley shaft  86 , which is supported by opposing yaw guide bearings  88  and  90 . 
     Yaw guide pulley  72  and opposing yaw guide pulley  76  serve to route yaw belt  68  to yaw motor drive pulley  74 , and forces yaw belt  68  close to yaw radius  60 . Yaw guide pulley shaft  80  also drives yaw sensor  92 , providing yaw position input to the computer. Yaw sensor  92  is shown as a multi-turn potentiometer, but other rotation sensors may also be used as previously mentioned. 
     Platform motor  94  ( FIG. 2 ) traverses platform  66  (and thus cockpit  10  and control panel  96 ) left and right along track  98  through drive wheels  100  and idler wheels  102 . Platform motor  94  drives drive wheels  100  through the platform drivetrain ( FIG. 5 ) which includes motor pulley  104 , drive belt  106 , drive shaft pulley  108 , and drive shaft  110 . The platform motor is preferably a reversing, variable speed ½ horsepower three-phase AC electric motor, similar to the roll and yaw motors previously described. Platform motor  94  is preferably controlled by a motor controller (not shown), such as a VFD, that determines the phasing and frequency of the power to the motor in order to control its direction and speed. 
     The on-board computer calculates the desired platform motor speed and direction and then preferably provides an appropriate signal to the controller to control it in a manner similar to the roll motor control scheme example described above. The speed and direction of the platform motor is computed by algorithms that process information such as roll position, yaw position, and introduced wind condition forces, to produce desired effects that duplicate conditions in a light aircraft near landing speed with a pilot at the controls. 
     The control panel  96  ( FIG. 1 ) is preferably attached to the back side of platform  66 , and contains the computer (not shown), power supply (not shown), and motor controllers (not shown) that control the roll, yaw, and platform motors. Instructor control station  114  is attached to the control panel  96  in such a way that a flight instructor can stand behind the entire simulator and adjust all parameters in real time. Instructor control station  114  preferably offers the following controls: Power, E-Stop, Yaw jog, Roll jog. Drift jog, Center All, run/stop, wind direction and speed, and wind gust (collectively, input switches). 
     In general, the computer receives position information from the yoke  14 , rudder pedals  16 , roll sensor  56  and yaw sensor  92 , as well as control information from the instructor control station  114  input switches (including wind speed, wind direction and gust magnitude), and processes them to determine movement of the simulator. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.