Patent Publication Number: US-2016240096-A1

Title: Motion device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a national stage filing of International patent application Serial No. PCT/AU2014/000917, filed Sep. 17, 2014, and published as WO 2015/039167 A1 on Mar. 26, 2015, in English. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a motion device. The present invention is particularly suitable for use as a motion simulating device such as a flight simulating device, however, it is to be appreciated that the present invention may have broader application such as in relation to simulating motion of vehicles other than aircraft, such as motor vehicles, boats, submersibles or the like. 
     BACKGROUND OF THE INVENTION 
     The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. 
     Motion simulating devices, such as flight simulators, are devices that artificially recreate the sensation of motion within a vehicle, such as an aircraft. Motion simulating devices such as flight simulators can also include means for recreating audio/visual sensations of flight in an aircraft as well as providing controls for enabling a user to provide inputs to control the simulated flight experience. Such devices are particularly useful for the training of pilots as well as in the design and development of aircraft and associated research into aircraft characteristics and control. Flight simulators typically employ hardware including a recreated aircraft cockpit and means for moving the cockpit in a manner that simulates up to six degrees of motion associated with aircraft flight including roll, pitch, yaw, heaving (moving up and down), swaying (moving left and right) and surging (moving forward and backward). 
     Existing motion simulators are generally large, complex and driven by hydraulics or pneumatics. Hydraulic and/or pneumatic actuators are employed to move the simulated cockpit in three-dimensional space so as to recreate at least some of the above mentioned degrees of freedom of motion. However, hydraulic and pneumatic actuators are typically loud as they require the rapid movement of fluid or gas into cylinders to actuate pistons. Furthermore, hydraulic and pneumatic actuators are relatively large and when employed to move a simulated cockpit typically require the cockpit to be mounted above a platform that is supported on a system of actuators. As such, the entire motion simulator device, including the simulated cockpit, can be several metres in height and thus requires a large enclosed structure to house the simulator device. Such motion simulating devices often require a purpose built structure in which to house the device due to their relative large space requirements. A six-degrees-of-freedom motion platform using five or six hydraulic or pneumatic actuators, known as a Stewart platform, is the gold standard for motion simulating devices. However, existing motion simulator devices, such as flight simulator devices, due to their complexity, size, power requirements and the like are expensive to acquire and maintain. 
     Some existing flight simulator devices employ electric motors as a means to generate motion of the simulated cockpit. Existing flight simulators employing electric motors as a means to provide motion include a replica cockpit cradled on a sub-frame supported on a base frame. The cockpit is pivotally connected to the sub-frame so as to provide for a first degree of freedom of motion in the form of roll motion of the cockpit relative to the sub-frame and the base frame. The sub-frame is connected to the base frame by a first pivotal connection so as to provide for a second degree of freedom of motion in the form of pitch motion of the cockpit and the sub-frame relative to the base frame. Furthermore, the sub-frame is connected to the base frame by a second pivotal connection to provide for a third degree of motion of the in the form of yaw motion of the cockpit and sub-frame relative to the base frame. As can be appreciated, such an arrangement still requires a relative large space in which to house the simulator device to enable movement of the cockpit and the sub-frame relative to the base frame. In particular, to provide space for the cockpit and the sub-frame to move in a yaw motion (side to side) relative to the base frame. Also, relatively powerful electric motors are required in order to shift the weight of the replica cockpit and sub-frame relative to the base frame. 
     SUMMARY OF THE INVENTION 
     This Summary and the Abstract herein are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and the Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background. 
     Accordingly, in one aspect, the present invention provides a motion device including: 
     a frame including a plurality of roller assemblies mounted thereto; and 
     an at least partially rounded body supported on the roller assemblies, wherein the roller assemblies are operable to contact an external surface of the body and to allow movement of the body in a pitch direction, a yaw direction and a roll direction relative to the frame. 
     In an embodiment one or more of the roller assemblies are selectively drivable to controllably drive the movement of the body in the pitch direction, the yaw direction arid the roll direction relative to the frame. 
     Embodiments of the invention provide for motion (i.e. rotation) of the body in the pitch, roll and yaw directions to be driven in a controlled fashion, which could include a desired direction such as the pitch, roll or yaw direction. Such control of motion of the body could include control of a speed of rotation and/or a rate of change of speed of rotation (i.e. acceleration). Embodiments of the invention may allow for control of a change of direction of rotation of the body. Embodiments of the invention may allow for control of the direction of rotation of the body to include a desired combination of simultaneous rotation in any one or more of the pitch, roll and yaw directions to thereby simulate such motion of a body in three dimensional space such as an aircraft in the air, a submersible underwater, and to some extent a motor vehicle on a road and a boat on the surface of water which also may experience motion in three the pitch, roll and yaw directions. 
     Each one of the roller assemblies can include a wheel rotatably mounted to the frame so as to rotate about a primary axis of rotation. Each one of the roller assemblies can also include circumferentially spaced apart roller members mounted to the wheel and radially spaced apart from the primary axis of rotation. Each one of the roller members rotates with the wheel about the primary axis of rotation and rotates relative to the wheel about a respective secondary axis of rotation that is transverse to the primary axis of rotation. At least part of the external surface of the body has a spherical shape with a constant radius from a central point, wherein the spherically shaped external surface contacts with at least one of the roller members and is thereby rotatable in any direction about the central point. 
     In an embodiment, the wheel can include a plurality of sets of the circumferentially spaced apart roller members, in each set the roller members lie in a plane and are the same radial distance apart from the primary axis of rotation. The planes of adjacent sets are parallel and the roller members of one set are a different radial distance apart from the primary axis of rotation than the roller members of an adjacent set. The difference between the radial distance apart from the primary axis of rotation of the roller members of the adjacent sets complements the curvature of the spherical shaped external surface of the body. The plurality of sets of the circumferentially spaced apart roller members provide a concave zone of contact between roller assembly and the external surface of the body. In a preferred form, the roller members of the adjacent sets are staggered relative to each other. 
     In an embodiment, rotation of one or more of the wheels about the primary axis of rotation is driven by a drive motor. In another embodiment, rotation of each one of the roller members relative to the wheel about its respective secondary axis of rotation is passive. 
     The roller assemblies are preferably mounted to the frame such that the primary axis of rotation is parallel to a tangent of the spherically shaped external surface of the body. The roller assembly is substantially biconcave in longitudinal section. 
     In one form, the device includes three of the roller assemblies mounted to the frame in a circle at 120 degree intervals. In another form, the device includes four of the roller assemblies mounted to the frame in a circle at 90 degree intervals. 
     Preferably, at least a portion of the external surface of the rounded body for engagement with the roller members is the shape of a segment of a sphere. 
     The device can also include a user control input for a user to select a movement of the rounded body in any one or a combination of the pitch direction, the yaw direction and the roll direction and a control system for determining a selection of the one or more roller assemblies to be driven to drive the selected movement of the rounded body. 
     Preferably, the motion device is a motion platform for a flight simulator apparatus. Accordingly, the rounded body may contain a simulated aircraft cockpit. 
     In another aspect, the present invention provides a method of operation of a motion device including a frame including a plurality of roller assemblies mounted thereto arid a rounded body supported on the roller assemblies wherein the roller assemblies are operable to contact an external surface of the rounded body and to allow movement of the rounded body in a pitch direction, a yaw direction and a roll direction relative to the frame, the method including selectively driving rotation of one or more of the roller assemblies to drive the movement of the rounded body in the pitch direction, the yaw direction and the roll direction relative to the frame. 
     Preferably, each one of the roller assemblies includes a wheel rotatably mounted to the frame so as to rotate about a primary axis of rotation and circumferentially spaced apart roller members mounted to the wheel and radially spaced apart from the primary axis of rotation, each one of the roller members rotates with the wheel about the primary axis of rotation and rotates relative to the wheel about a respective secondary axis of rotation that is transverse to the primary axis of rotation, wherein selectively driving rotation of one or more of the roller assemblies includes selectively driving rotation of one or more of the wheels about the primary axis of rotation. 
     The method preferably includes selectively driving rotation of one or more of the wheels about the primary axis of rotation in a clockwise or a counter clockwise direction at a determined speed of rotation. In yet another preferred embodiment, the method includes receiving a user control input indicative of a selected movement of the rounded body in any one or a combination of the pitch direction, the yaw direction and the roll direction; arid determining a selection of the one or more roller assemblies to be driven to drive the selected movement of the rounded body. Determining a selection of the one or more roller assemblies to be driven to drive the selected movement of the rounded body preferably includes determining the speed and direction of rotation of one or more of the roller assemblies about their respective primary axes of rotation. 
     In yet another aspect, the present invention provides a roller assembly adapted to be mounted to a frame and for contacting an external surface of an at least partially rounded body to allow movement of the body in a pitch direction, a yaw direction and a roll direction relative to the frame, the roller assembly including: 
     a wheel rotatably mounted to the frame so as to rotate about a primary axis of rotation; and 
     circumferentially spaced apart roller members mounted to the wheel and radially spaced apart from the primary axis of rotation, each one of the roller members rotates with the wheel about the primary axis of rotation and rotates relative to the wheel about a respective secondary axis of rotation that is transverse to the primary axis of rotation; 
     wherein at least part of the external surface of the body has a spherical shape with a constant radius from a central point, wherein the spherically shaped external surface contacts with at least one of the roller members and is thereby rotatable in any direction about the central point. 
     The wheel can include a plurality of sets of the circumferentially spaced apart roller members, in each individual set the roller members lie in a plane and are the same radial distance apart from the primary axis of rotation, and the roller members of adjacent sets lie in parallel planes and are different radial distances apart from the primary axis of rotation. 
     The difference between the radial distance apart from the primary axis of rotation of the roller members of adjacent sets preferably complements the curvature of the spherical shaped external surface of the body. 
     Preferably, the plurality of sets of the circumferentially spaced apart roller members provide a concave zone of contact between roller assembly and the external surface of the body. 
     Preferably, the roller members of the adjacent sets are staggered relative to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the present invention will now be described in more detail with reference to the preferred embodiments of the invention set out in the accompanying Figures, in which: 
         FIG. 1  illustrates a perspective view of a motion device in accordance with an embodiment of the invention, wherein the motion device is a flight simulator; 
         FIG. 2  illustrates a perspective view of the motion device of  FIG. 1 , wherein a portion of a shroud is removed that surrounds a rounded body containing a replica aircraft cockpit supported on four roller members connected to a frame; 
         FIG. 3  illustrates a perspective view of the motion device of  FIG. 1 , wherein the entire shroud and a portion of the rounded body have been removed to reveal the arrangement of the replica cockpit contained within the rounded body; 
         FIG. 4 a    illustrates a top view of the motion device of  FIG. 1 , illustrating, in particular, the rounded body supported on roller assemblies and a frame and the location of the roller assemblies in a circle at 120 degree intervals; 
         FIG. 4 b    illustrates a side view of a section of the motion device taken along section line  4   b - 4   b  of  FIG. 4   a,  illustrating, in particular, the rounded body supported on the roller assemblies and the frame; 
         FIG. 5  illustrates a perspective view of one of the roller assemblies of the motion device of  FIG. 1 ; 
         FIG. 6  illustrates a front view of the roller assembly of  FIG. 5 ; 
         FIG. 7 a    illustrates a cross section of the roller assembly of  FIG. 5 ; 
         FIG. 7 b    illustrates a partially exploded perspective view of the roller assembly of  FIG. 5 ; 
         FIG. 8  illustrates a longitudinal section view of the roller assembly of  FIG. 5  and a concave zone of contact between roller assembly and the external surface of the body, although it is to be appreciated that in  FIG. 8  the aligned relative positioning of roller members in adjacent sets is not representative of the staggered positioning of the roller members of embodiments illustrated in other figures; 
         FIG. 9  illustrates a side view of a portion of the motion simulating device of  FIG. 1 , including a portion of the body supported on one of the roller assemblies which in turn is supported on the frame and coupled to a drive means. 
     
    
    
     The present invention will now be described in more detail below with reference to the preferred embodiments of the invention illustrated in the Figures. 
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
     Referring to  FIGS. 1 to 3, 4   a  and  4   b,  there is shown a motion device  10  in accordance with a preferred embodiment of the invention. The motion device  10  is in the form of a flight simulator although it is to be appreciated that embodiments of the motion device  10  could be configured for use to simulate motion of other vehicles, such as motor vehicles, boats, submersibles or the like. The device  10  includes a frame  12  and a plurality of roller assemblies  40  mounted to the frame  12  and an at least partially rounded body  30  supported on the roller assemblies  40 . Each one of the roller assemblies  40  is operable to contact an external surface  32  of the body  30  and to allow movement of the body  30  in a pitch direction, a yaw direction and a roll direction relative to the frame  12 . As will become apparent from the foregoing description, in embodiments of the invention, the roller assemblies  40  are selectively drivable to drive movement of the body  30  in a pitch direction, a yaw direction and a roll direction and any combination thereof relative to the frame  12 . Thus, as illustrated in  FIG. 3  the motion device  10  provides for three degrees of freedom of rotation of the body  30  in the pitch, roll and yaw directions about the Y, X and Z axes respectively relative to the frame  12  and a surface or support upon which the frame  12  rests or is supported. 
       FIGS. 5 to 8  illustrate an embodiment of the roller assembly  40  as used in the motion device  10 . The roller assembly  40  includes a wheel  42  and a plurality of roller members  52 . The wheel  42  is rotatably mounted to the frame  12 , as illustrated in  FIGS. 1 to 3 ,  4   a,    4   b  and  9  so as to rotate about a primary axis of rotation X-X of the wheel  42 . As shown in  FIGS. 5, 7   a  and  7   b  in particular, the plurality of roller members  52  are mounted to the wheel  42  in a circumferentially spaced apart fashion and also radially spaced apart from the primary axis of rotation X-X. Thus, each one of the roller members  52  rotates with the wheel  42  about the primary axis of rotation X-X. Also, each one of the roller members  52  rotates relative to the wheel  42  about its own respective axis of rotation, referred to herein as a secondary axis of rotation Y-Y as illustrated in  FIG. 7   a.  The respective secondary axis of rotation Y-Y of each roller member  52  is transverse to the primary axis of rotation X-X. It is to be appreciated that each individual roller member  52  of the roller assembly  40  has its own secondary axis of rotation Y-Y which may run in the same direction as, but will not be aligned with, the secondary axis of rotation Y-Y of other roller members  52  of the same roller assembly  40 . 
     Referring to  FIGS. 5, 6, 7   a  and  7   b,  the roller members  52  are rotatably mounted near and about the circumference of the wheel  42  and are each operable to rotate about their respective secondary axes of rotation Y-Y. As illustrated in  FIG. 7   a,  the secondary axes of rotation Y-Y of the roller members  52  are along secant lines cutting across the circumference of the wheel  42 . Thus, the secondary axes of rotation Y-Y of the roller members  52  are perpendicular to a radius extending from the primary axis of rotation X-X of the wheel  42 . In the embodiments illustrated in the Figures, the secondary axes of rotation Y-Y of the roller members  52  are also at an angle of about 90 degrees to the primary axis of rotation X-X of the wheel  42 . It is to be appreciated, however, that the secondary axes of rotation Y-Y of the roller members  52  may run at any angle relative to the primary axis of rotation X-X of between 0 and 90 degrees such that the roller members  52  can rotate in a direction at an angle transverse to the direction of rotation of the wheel  42 . Thus, the roller members  52  are operable to rotate relative to the wheel  42  and are also operable to rotate with the wheel  42  about the primary axis of rotation X-X. 
     As can be seen in  FIGS. 5, 6, 7   b  and  8 , the roller assembly  40  includes a plurality of sets  50  of the circumferentially spaced apart roller members  52 . In each one of the sets  50 , the roller members  52  lie in a plane. The planes in which the roller members  52  of each set  50  lie are parallel to each other and perpendicular to the axis of rotation X-X of the wheel  42 . Thus, the roller assembly  40  includes a plurality of sets  50  of the roller members  52  arranged in parallel planes. The roller members  52  within each set  50  are circumferentially spaced apart and are equidistant (i.e. the same radial distance apart) from the primary axis of rotation X-X. 
     As can be seen in  FIGS. 5, 6, 7   b  and  8  the roller assembly  40  includes a plurality of adjacent sets  50  of the circumferentially spaced apart roller members  52 . The roller members  52  of one of the sets  50  are a different radial distance apart from the primary axis of rotation than the roller members  52  of one or both adjacent sets  50 . Furthermore, the roller members  52  of each of the sets  50  are staggered relative to the roller members  52  of the adjacent set  50 . A space  53  is provided between adjacent roller members  52  within a set  50  by virtue of their circumferential spacing. The space  53  is traversed or spanned by one of the roller members  52  of the adjacent set  50 . Thus, when the external surface  32  of the body  30  rests upon the roller assembly  40 , regardless of the relative rotational position of the wheel  42  of the roller assembly  40  to the external surface  32  of the body  30 , at any time the external surface  32  will be in contact with at least one of the roller members  52  of at least one of the sets  50 . 
       FIG. 7 a    illustrates a cross section of the roller assembly  40 . In each of the roller assemblies  40 , the roller members  52  are rotatably mounted to the wheel  42  by way of an axle member  54 . The axle member  54  is an elongated rod having a bend  55  at a mid-point along the axle member  54 . The axle  54  has two ends  56 ,  57  that are on opposite sides of the bend  55 . The axle  54  is mounted to the wheel  42  and a pair of the roller members  52  are rotatably mounted to the ends  56 ,  57  of the axle  54 . Thus, the roller members  52  mounted to the axle member  54  are operable to rotate about their own individual (i.e. respective) axis of rotation Y 1 -Y 2 , Y 2 -Y 2  at an angle to each other equivalent to the angle of the bend  55  of the axle member  54 . 
       FIG. 7 b    illustrates a partially exploded perspective view of the roller assembly  40  illustrating how the roller assembly  40  is comprised of a plurality of wheel segments  242 . Each wheel segment  242  includes a central passage  244  and a radially outwardly extending support member  246  extending to a plurality of circumferentially spaced apart bearing surfaces  255 . Between successive pairs of bearing surfaces  255  is a recess  256 . Pairs of the wheel segments  242  are brought together such that their central passages  244  are aligned about the primary axis of rotation X-X of the wheel  42  and bearing surfaces  255  and recesses  256  of the adjacent wheel segments  242  also are aligned to receive the axles  54  and the roller members  52 . The aligned bearing surfaces  255  of adjacent wheel segments  242  capture the axles  54  whereby the bend  55  is received between one pair of aligned bearing surfaces  255  and the two ends  56 ,  57  are received between other pairs of aligned bearing surfaces  255 . The roller members  52  are rotatably mounted to the two ends  56 ,  57  of the axle members  54  and are located within aligned pairs of recesses  256 . The roller members  52  protrude radially outwardly from the aligned recesses  256  about a circumference of the assembled wheel  42  so as to provide one of the sets  50  of roller members  52 . As can be seen in  FIGS. 5, 6 and 7   b  the wheel  42  is assembled to include a plurality of the sets  50  of the roller members  52  by assembling a plurality of adjacent wheel segments  242 , axle members  54  and roller members  52  as described above. 
     As can be seen in  FIGS. 6, 7   b  and  8 , the radial distance from the primary axis of rotation X-X of all of the roller members  52  in each set  50 , considered separately, is the same. However, the radial distance of the roller members  52  from the primary axis of rotation X-X in one set  50  is different to that of an adjacent set  50 . The embodiment of the roller assembly  40  illustrated in  FIGS. 5, 6, 7   b  includes five sets  50  of roller members  52  in which the roller members  42  in the middle set  50  are radially spaced apart from the primary axis of rotation X-X by the smallest distance. The roller members  42  of the sets  50  either side of the middle set  50  are radially spaced apart from the primary axis of rotation X-X by a larger distance than the middle set  50 . The roller members  42  of the sets  50  at opposite ends of the wheel  42  are radially spaced apart from the primary axis of rotation X-X by a larger distance than the sets  50  either side of the middle set  50 . The difference between the radial distances of the roller members  52  apart from the primary axis of rotation X-X of adjacent sets  50  is related to, and thereby complements, the curvature external surface  32  of the body  30 . Thus, as illustrated in  FIG. 8 , the sets  50  of the roller members  52  define a concave zone of contact  58  between the roller assembly  40  and the external surface  32  of the body  30 . The concave zone of contact  58  complements the curvature of the spherical shaped external surface  32  of the body  30  so as to ensure that the roller members  52  of each of the sets  50  can contact the external surface  32  of the rounded body  30 . 
     Preferably, the roller assembly  40  includes five sets  50  of the roller members  50  as with this configuration at least two roller members  52  of two different sets  50  are in contact with the external surface  32  of the body  30  at any given time. Such is advantageous in providing sufficient friction between the roller assembly  40  and the external surface  32  of the body  30  to enable effective and controlled driving of rotational motion of the body  30  as described herein. However, the roller assembly  40  could include other odd numbers of sets such as three or seven etc. or it could include even numbers of sets such as two, four six etc. 
     In the embodiments of the motion device  10  illustrated in the Figures, at least part of the external surface  32  of the body  30  has a spherical shape with a constant radius from a central point (not shown). The spherically shaped external surface  32  is supported on and contacts the roller members  52  of the roller assembly  40 . It is to be appreciated that the entire external surface  32  of the body need not be spherical but rather only the part or parts that contact the roller members  52 . In an embodiment, at least a portion of the external surface  32  of the body  30  for engagement with the roller members  42  is the shape of a segment of a sphere. Given that the wheel  40  of the roller assembly  40  is operable to rotate about the primary axis of rotation X-X and the roller members, upon which the external surface  32  is supported, are operable to rotate about the secondary axis of rotation Y-Y, which is transverse and preferably 90 degrees to the primary axis of rotation X-X, the external surface  32  is rotatable in any direction about the central point. To put it another way, the rotation of the wheel  40  relative to the external surface  32  of the body  30  about the X-X axis provides for rotation of the body  30  in a first direction (i.e. an X axis) whilst rotation of the roller members  52  relative to the external surface  32  of the body  30  about their secondary axes of rotation Y-Y provides for rotation of the body  30  in a second direction (i.e. a Y axis). Thus, the roller assembly  30  facilitates movement of the external surface  32  of the body  30  relative to each one of the roller assemblies  30  in any direction in the X and Y (i.e. horizontal and vertical) axes. Because the external surface  32  of the body  30  is rounded and preferably spherical the movement of the body  30  is rotational, in any direction, about the central point of the spherical surface. 
     As illustrated in  FIGS. 2, 3 and 4   a,  the device  10  includes three of the roller assemblies  40  mounted to the frame  12  in a circle at 120 degree intervals. In another embodiment, not illustrated, the device  10  could include four of the roller assemblies  40  mounted to the frame  12  at 90 degree intervals. In other embodiments, not illustrated, the device  10  includes five or six or seven or eight or nine or more of the roller assemblies  40  mounted to the frame  12 . An arrangement including three of the roller assemblies  40 , or an odd number of the roller assemblies  40  such as five or seven etc. is preferable. This is because it was discovered that the adoption of an even number of roller assemblies  40  could result in an undesirable rocking of the body  30  on directly opposite pairs of the roller assemblies  40  which occurs in arrangements including even numbers of the roller assemblies  40  located equidistant intervals from each other. Nevertheless, it is to be appreciated that even numbers of roller assemblies  40  such as four, six etc. could be employed. 
     Furthermore, each one of the roller assemblies  40  is coupled to a respective drive means  60 , such as an electric or pneumatic motor or like device, capable of driving rotation of the roller assembly  40 , including the wheel  42  and the roller members  52  mounted thereto, about the primary axis of rotation X-X thereof. Rotation of each roller assembly  40  can be selectively driven by the drive means  60  in the clockwise or anti-clockwise directions about the primary axis of rotation X-X. Each roller assembly  40  can also passively rotate in the clockwise or anti-clockwise directions about the primary axis of rotation X-X. Rotation of each of the roller members  52  about their secondary axis of rotation Y-Y relative to the wheel  42  is passive but could also be driven by a drive means (not shown). 
     As will be described below, the various drive means  60  can be controlled so as to drive rotation of each of the three roller assemblies  40  about their respective primary axis of rotation X-X in a manner so as to drive movement (i.e. rotation) of the body  30  relative to the frame  12  in the pitch direction, the yaw direction and the roll direction, one at a time or in any combination thereof simultaneously. 
     For example, in the case where there are three or four of the roller assemblies  40 , if all three drive means  60  associated with all three or four roller assemblies  40  are simultaneously operated to drive rotation of the roller assemblies  40  in the same direction about their respective primary axis of rotation X-X (i.e. clockwise or anticlockwise) then the body  30  will be caused to rotate in a yawing motion, that is to turn left or right depending on the direction of rotation of the roller assemblies  40 . 
     In the case where there are four of the roller assemblies  40 , operation of two of the drive means  60  associated with two of the roller assemblies  40  located on opposite sides of the body  30  and spaced apart by 180 degrees from each other, such as on the left and right hand sides of the body  30 , so as to cause rotation of the two roller assemblies  40  in opposite directions about their respective primary axis of rotation X-X (i.e. clockwise and anticlockwise) will cause movement of the body  30  in a pitching motion, that is tilting forward or backward, depending on the direction of rotation of the roller assemblies  40 . In respect of the remaining two non-driven roller assemblies  40 , which are also on opposite sides of the body  30  and that are spaced apart at 90 degree intervals to the driven roller assemblies  40 , the roller members  52  are operable to passively rotate about their secondary axis of rotation Y-Y transversely relative to the wheels  42 . Thus, the passively rotatable roller members  42  allow the external surface  32  of the body  30  to move transversely relative to the wheels  42  of the non-driven roller assemblies  40 . The non-driven roller assemblies  40  do not hinder the movement of the body  30  in the transverse direction relative to the wheels  42 . Similarly, operation of the drive means  60  associated with the previously non-driven roller assemblies  40 , which are located on opposite sides of the body  30  and at 90 degree intervals to the previously driven pair of the roller assemblies  40 , so as to cause rotation of the two roller assemblies  40  in opposite directions about their respective primary axis of rotation X-X (i.e. clockwise and anticlockwise) will cause movement of the body  30  in a rolling motion, that is tilting side to side. Similarly as for the pitching motion of the body  30 , when the body  30  moves in the rolling motion the roller assemblies  40  that are not being driven do not hinder the movement of the body  30  in the transverse direction relative to the wheels  42 . 
     In the case where there are three of the roller assemblies  40 , such as is illustrated in the Figures, operation of the drive means  60  associated with the three roller assemblies  40  to cause the movement of the body  30  in the pitch direction, the yaw direction and the roll direction, one at a time or any combination thereof simultaneously, is somewhat more complicated. For example, in the case where there are three of the roller assemblies  40 , if all three drive means  60  associated with all three of the roller assemblies  40  are simultaneously operated to cause rotation of the roller assemblies  40  in the same direction about their respective primary axis of rotation X-X (i.e. clockwise or anticlockwise) then the body  30  will be caused to move in a yawing motion, that is to turn left or right depending on the direction of rotation of the roller assemblies  40 . 
     In the case where there are three of the roller assemblies  40 , operation of two of the drive means  60  associated with two of the roller assemblies  40  located and spaced apart by 120 degrees from each other, such as on the left rear and right rear of the body  30 , so as to cause rotation of the two roller assemblies  40  in opposite directions about their respective primary axis of rotation X-X (i.e. clockwise or anticlockwise) will cause movement of the body  30  in a pitching and/or rolling motion, that is tilting forward or backward or side to side or a combination thereof, depending on the direction of rotation of the roller assemblies  40 . If the speed of rotation of the roller assemblies  40  is identical then the body  30  will pitch in a direction bisecting the angular displacement between the roller assemblies  40  that are so driven. If the speed of rotation of the driven roller assemblies  40  is not the same then this will alter the direction of pitch of the body  30  to some direction between the two driven roller assemblies  40 . Thus, depending on which two roller assemblies  40  are being so driven in opposite directions about their respective primary axis of rotation X-X and depending on the relative speed of such rotation will determine the direction of pitch or roll or both of the body  30  which may be in any direction in 360 degrees about the body  30 . 
     In each of the scenarios described above with respect to the embodiment comprising three of the roller assemblies  40 , in respect of the remaining non-driven roller assembly  40  the passively rotatable roller members  52  which are operable to rotate transversely about their secondary axes of rotation Y-Y relative to the wheels  42 , enables the external surface  32  of the body  30  to freely move transversely relative to the wheels  42  of the non-driven roller assembly  40 . Thus, the non-driven roller assembly  40  does not hinder the movement of the body  30  in the transverse direction relative to the wheels  42 . 
     As can be appreciated, rotation of various combinations of the roller assemblies  40  in various combinations of directions can be driven by the various drive means  60  so as to cause rotation of the body  30  relative to the frame  12  in the pitch direction, the yaw direction and the roll direction, one at a time or any combination thereof simultaneously. Thus, the body  30  provides a platform for a simulated aircraft cockpit  36 , such as is illustrated in  FIGS. 1 to 3 , whereby a person within the simulated cockpit  36  can experience 3 degrees of freedom of motion in the pitching direction, the yawing direction and the rolling direction. 
     It is to be appreciated that any form of roller member capable of enabling the body  30  to rotate about the central point by allowing the body  30  to roll over the roller member in any direction could fall within the scope of the present invention. In this regard, another example of a roller member that could be employed in the present invention is a Mecanum wheel and any other form of omni-wheel or poly-wheel capable of enabling the rounded body  30  to roll over the roller member in any direction yet being capable of being rotatably driven about at least one axis of rotation. However, it has been found that the embodiments of the roller assemblies  40  disclosed herein are advantageous over other roller assemblies because, for example: they are able to be manufactured at less expense and are less complex than other solutions such as Mecanum wheels; they are capable of supporting the weight of the rounded body including internal cockpit components and the weight of one or more users; they are capable of driving rotation of the body  30  in the pitch, roll and yaw directions with sufficient accuracy and speed to provide for the realistic sensation of movement. In any event, whilst other forms of roller assemblies might be capable of driving rotation of the body  30  with three degrees of freedom of movement such roller assemblies have, hitherto, only been used for the purpose of moving a vehicle over a surface or as stationary rollers for allowing objects to translate over the stationary rollers in different directions in two dimensions. 
     As mentioned above and as illustrated in  FIGS. 1 to 4 and 9 , at least a portion of the external surface  32  of the body  30  that is for engagement with the roller assemblies  40  is the shape of a segment of a sphere. For example, as illustrated in the embodiment of  FIGS. 1 to 4 and 9  the external surface  32  of the body  30  includes a spherical lower-most portion. The simulated cockpit  36  is mounted within the body  30  and an uppermost portion of the rounded body  30  also has a spherical shape, though it need not be so, to enclose simulated cockpit  36  within the body  30 . The body  30  includes an access opening  31  that is operable to enable a person to access the simulated cockpit  36  within the body  30 . A door  33  is provided to open and close the access opening  31 . 
     The frame  12 , upon which the plurality of drive means  60 , roller assemblies  40  and the body  30  are mounted and supported, includes, as illustrated in the  FIGS. 1 to 3, 4   a  and  4   b,  where there are three roller assemblies  40  a trio of support members  13 ,  14  that are arranged perpendicular to each other. The frame  12  further includes a base plate  15  upon which the support members  13  are mounted. The roller assemblies  40  are mounted to the support members  13  such that the primary axis of rotation X-X of each of the roller assemblies  40  is at an incline relative to the horizontal and to the base plate. The angle at which the primary axis of rotation X-X of each of the roller assemblies  40  is mounted relative to the horizontal may be any suitable angle such as 30° or 45° or any angle between 0° and 90° and preferably at an angle that is tangential to the curvature of the spherical portion of the external surface  32  of the body  30 . 
     The drive means  60  associated with each one of the roller assemblies  40  is controlled by a control system (not shown) which may include a computerised control system that is operable to variously operate the drive means  60  to cause rotation of one or more of the roller assemblies  40  in either rotational direction about their primary axes of rotation X-X. The control system is operable to receive instructions from a user control input  7 , such as a flight control stick, wheel (not shown) or pedals  8  in the simulated cockpit  36 , indicative of a selected movement of the rounded body in any one or a combination of the pitch direction, the yaw direction and the roll direction. A user operates the use control input  7  in the appropriate manner, such as tilting the stick and/or depressing one or other of the pedals, to select a desired movement of the body  30  in any one or a combination of the pitch direction, the yaw direction and the roll direction. The control system receives a signal from the user control input indicative of a selected movement of the rounded body in any one or a combination of the pitch direction, the yaw direction and the roll direction and determines a selection of the one or more roller assemblies  40  to be driven, and the direction and speed of rotation of each of the one or more roller assemblies, to drive the selected movement of the body  30 . The control system selectively causes the drive means  60  to drive rotation of one or more of the roller assemblies  40  according to the determination made as to which of the one or more roller assemblies  40  must be driven to drive the selected movement of the body  30 . 
     The control system is operable to control the drive means  60  so as to cause the rounded body  30  to move in the pitch direction, the yaw direction and the roll direction relative to the frame  12 , or any combination thereof either simultaneously or separately, so as to simulate the sensation of flying an aircraft, or in the case of motion simulating devices other than flight simulators, driving a motor vehicle or the like. The control system is responsive to user inputs into control inputs  7  such as a flight control stick, wheel, pedals or the like mounted within the simulated cockpit  36  to move the rounded body  30 , and the cockpit  36 , in response to the user inputs and in response to other input from software replicating the movement of a simulated aircraft in a simulated environment. The user control devices  7 , which may include devices such as a wheel, stick, pedals, levers, switches and the like are connected either via a wired connection or a wireless connection to the control system to transmit user inputs to the control system. 
     The present invention is advantageous in that it provides a motion device that, in an embodiment, can be configured as a flight simulator that can recreate three degrees of motion namely pitch, roll and yaw. Another advantage of the present invention, is that the rounded body containing the cockpit is moved in the pitch, roll and yaw directions about a central point which remains stationary thus meaning that the entire weight of the rounded body and the cockpit and a person contained therein, need not be shifted away from the central point so as to recreate the yaw motion in particular. Thus, the present invention requires less powerful motors and less energy to simulate the yaw motion for example. Furthermore, the present invention provides a motion device that is relatively compact, requires a relatively smaller space in which to operate in comparison to existing motion devices configured for use as a flight simulator providing the pitch, roll and yaw degrees of freedom of motion. Thus, the present invention, in the form of a flight simulator device, can be contained within a room of an existing building and does not require an oversize or purpose built room to contain it. Also, in an embodiment of the motion device which is covered by a shroud, the device may be located outdoors and is protected from the elements by the shroud. Furthermore, by utilising motors such as electric motors to recreate motion, embodiments of the present invention can be less noisy and more cost effective to operate and maintain than existing motion devices using hydraulic or pneumatic linear actuators. 
     It is to be understood that various alterations, modifications and/or additions may be made to the method and/or to the lightweight panel without departing from the ambit of the present invention as disclosed herein.