Patent Publication Number: US-2003224333-A1

Title: Suspended Motion system simulation theater

Description:
TECHNICAL FIELD  
       [0001] This invention relates generally to simulators, and more particularly to simulators for training on crane machinery and equipment used to move large and/or heavy objects.  
       BACKGROUND  
       [0002] Cranes are machines that are used to move large or heavy objects from one location to another. For example, in the marine industry, supplies from ships are carried in containers and large tanks (e.g., for the transportation of water and oil). When the ships arrive at a port, these containers and tanks must be moved from the ship to the dock, a train, or another ship, and later may be moved from a dock to other transportation vehicles such as trucks, trains, or other ships, as examples. A harbor crane is typically used to move these supplies from ships. Cranes are also used in construction to move steel beams and concrete members, and in the petroleum industry to move and position pipes, for example.  
       [0003] Operators of crane equipment must be extensively trained, because mistakes made while operating a crane can be dangerous and costly, costing lives and damaging the items being moved, objects in the surroundings, or the crane equipment itself. Training on actual cranes is costly, taking away from revenue-generating time on cranes and causing wear and tear on the crane. Therefore, simulators are often used to train crane operators.  
       [0004] One type of prior art crane simulators includes a software system implemented on a laptop or personal computer, for example. A joystick is used to maneuver the simulated crane, and images on the screen respond accordingly. However, this type of software does not provide the crane operator with a very wide field of vision for viewing the object being moved, the surroundings, or the various parts of the crane equipment.  
       [0005] Another type of simulator comprises a cabin similar to the cabin of actual crane equipment, with screens placed in front of the cabin. An operator enters the cabin and sits in a chair with a view of an environment similar to an actual crane cabin being projected on the screen. As the operator moves the controls, the images on the screen simulate what the crane operator would see while operating an actual crane. In some prior art crane simulators, the cabin is mounted on top of a motion base, and the cabin is moved by the motion base according to the operator&#39;s control choices, coordinated with the images on the screen. While this type of crane simulator gives the crane operator a more realistic feel of operating a crane, however, because the motion base is placed beneath the cabin, the field of vision below the cabin is limited. A full-sized screen cannot be placed beneath the cabin because the motion base resides there.  
       SUMMARY  
       [0006] Embodiments of the present invention achieve technical advantages as a crane simulator having a cabin suspended from a frame or the ceiling of a room. A motion actuator is disposed between the cabin and the frame or ceiling. The field of vision of the operator is increased so that the operator is able to view a scene below the cabin, through a window in the cabin floor or through a steep front window, as examples.  
       [0007] In one embodiment, a simulator includes a cabin adapted to accommodate at least one person, the cabin comprising a control mechanism and a plurality of windows, a screen disposed proximate the cabin windows, and a motion actuator coupled to the cabin, wherein the cabin is suspended downwardly from the motion actuator, and wherein the motion actuator is adapted to move the cabin in response to adjustments made to the control mechanism.  
       [0008] In another embodiment, a virtual reality simulator for training a crane operator includes a cabin having a front, back, sides, bottom and top. The cabin includes a plurality of windows on at least the cabin front and sides, with the cabin being similar to an actual crane cabin. A chair is disposed within the cabin, wherein the crane operator may be seated in the chair. A steering mechanism is disposed proximate the chair, the steering mechanism being adapted to control the movement of the crane cabin. A control mechanism is disposed proximate the chair, wherein the control mechanism is adapted to control the operation of the crane. A screen is viewable by the operator through the cabin windows, and a plurality of projectors are disposed proximate the screen adapted to project images onto the screen. A motion actuator is coupled to the cabin top, wherein the cabin is suspended downwardly from the motion actuator, and wherein the motion actuator is adapted to move the crane and cabin in response to adjustments made to the control mechanism and steering mechanism. Images projected onto the screen correspond to the adjustments made and movement of the cabin.  
       [0009] In another embodiment, a method of manufacturing a virtual reality crane simulator includes providing a cabin having a plurality of windows, the cabin being similar to an actual crane cabin. The cabin is suspended from a motion actuator, and a screen is disposed proximate the windows, wherein the screen includes a viewing area that is underneath the cabin. The method includes providing a plurality of projectors adapted to project images onto the screen, attaching a chair to the cabin floor, and installing a control mechanism proximate the chair. A control system is coupled to at least the motion actuator, projectors, and control mechanism, wherein the control system is adapted to coordinate the cabin movement and projector images in response to adjustments made to the control mechanism.  
       [0010] Advantages of embodiments of the present invention include providing a crane simulator having a full simulated view out beneath the cabin, on the screen. Because the cabin is suspended from the motion actuator, the view beneath the cabin is not impeded, giving a more realistic and complete view of the objects, crane and scenery beneath the crane cabin and thus, providing improved training for crane operators. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011] The above features of embodiments of the present invention will be more clearly understood from consideration of the following descriptions in connection with accompanying drawings in which:  
     [0012]FIG. 1 illustrates a cabin simulator theater in accordance with an embodiment of the present invention, having a cabin suspended from a motion actuator and screens disposed over the cabin windows;  
     [0013]FIG. 2 shows a view of the inside of the cabin shown in FIG. 1, with cabin window screens visible to the operator on the cabin front, sides and floor, and a control panel positioned on either side of a steering wheel;  
     [0014]FIG. 3 illustrates a more detailed view of the left and right control panels shown in FIG. 2;  
     [0015]FIG. 4 shows a detailed perspective view of a motion actuator having motors disposed on a lower portion of a plurality of pistons;  
     [0016]FIG. 5 shows a cross-section of an embodiment of the motion actuator wherein the motors are disposed on an upper portion of the pistons, proximate the frame;  
     [0017]FIG. 6 shows a perspective view of a cabin simulator theater in accordance with another embodiment of the present invention, wherein a spherical screen is disposed around the cabin;  
     [0018]FIG. 7 shows a perspective view of the back of the cabin simulation theater shown in FIG. 6;  
     [0019]FIG. 8 shows a back view of a cabin simulation theater having an opaque spherical screen in accordance with an embodiment of the present invention, wherein a plurality of projectors are used to directly project images onto the spherical screen;  
     [0020]FIG. 9 shows a perspective view of the spherical screen of FIG. 8; and  
     [0021]FIG. 10 illustrates a block diagram of the system according to embodiments of the present invention. 
    
    
     [0022] Corresponding numerals and symbols in the different figures refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the preferred embodiments and are not necessarily drawn to scale.  
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
     [0023] A description of preferred embodiments of the present invention will be discussed, followed by a discussion of some advantages of the invention.  
     [0024]FIG. 1 shows a perspective view of a cabin simulation theater  100 , or a virtual reality crane simulator, in accordance with a first embodiment of the present invention, wherein a cabin  112  is suspended from a motion actuator  120 . Preferably the cabin  112  comprises a layout that is substantially similar to, or exactly the same as, the cabin of the crane equipment that an operator is being trained to control. For example, the cabin  112  may comprise an actual cabin from crane equipment, and may include the same windows  114  disposed thereon. The windows  114  may include front, window, side, back and bottom windows, as shown. The cabin  112  preferably comprises a plurality of relatively large windows  114  disposed on the front, sides and bottom, so that the operator has a wide field of vision while operating the crane simulator  100 .  
     [0025] A chair  134  is fixedly attached to the cabin  112  floor adjacent a floor window  114 . The chair  134  may be reclineable and may be adapted to pivot about a fixed axis, for example. The chair  134  may include two armrests, and alternatively, the chair  134  may not include armrests, for example. A control mechanism or panel  132 , (not shown in FIG. 1; see FIG. 2) is attached to the cabin floor or chair  134 , as examples, proximate the chair  134  and within the reach of the operator. The operator may enter the cabin  112  through a door disposed in the back of the cabin  112 , using a stair or ladder (not shown).  
     [0026] In accordance with the embodiment of the invention, the motion actuator  120  is fixedly coupled to a support frame  118  or ceiling. The support frame  118  may comprise a plurality of first beams attached e.g. welded or formed at a ninety degree angle to a plurality of second beams, for example. The support frame  118  preferably comprises steel, and alternatively may comprise other materials such as aluminum, stainless steel, carbon fiber, or plastic, as examples. Preferably, the frame  118  comprises a material that is light, for ease of transport, yet strong enough to support the weight of the actuator  120 , the cabin  112 , the operator, and any necessary electronics.  
     [0027] The motion actuator  120  may comprise an upper attachment member  122  in a top region adapted to mechanically couple the motion actuator  120  to the frame  118  or ceiling. The motion actuator  120  also may comprise a lower attachment member  124  in a bottom region adapted to mechanically couple the motion actuator  120  to the cabin  112 . The motion actuator  120  includes a plurality of pistons  126  coupled between the upper and lower attachment members  122 / 124 . The pistons  126  may be expanded or retracted in response to signals from a control system  460  (see FIG. 10) in order to raise or lower the cabin  112  at different angles, according to the operator&#39;s use of the control mechanism  132  (see FIG. 2).  
     [0028] In the embodiment shown in FIG. 1, the windows  114  are covered with a plurality of screens  116 . The screens  116  are preferably translucent so that an image may be projected onto the screens  116  from the outside of the cabin  112 , wherein the projected image may be viewed by the operator inside the cabin  112 , for example. The screens  116  may comprise a flexible material such as canvas, and alternatively may comprise plastic or glass, as examples. The screens  116  preferably include a viewing area that is underneath the cabin, e.g., on a window on the bottom floor of the cabin, or through a steep front window of the cabin.  
     [0029] A plurality of projectors  128  is preferably disposed about the exterior of the cabin  112 , with the projectors  128  being adapted to project an image upon the screens  116  of the cabin  112 . For example, projector  128   a  is adapted to project an image on the back screen  116 , so the operator may turn his head around and view the image projected on the back window  114 . Similarly, projector  128   b  is adapted to project an image onto the cabin right side screen  116 , and projector  128   c  is adapted to project an image onto the cabin front screen  116 . Mirrors  130  may also be used to project the images; for example, an image may be projected by projector  128   d  onto a mirror  130  that transfers the image to the cabin bottom window, as shown. The images of the plurality of projectors  128  are coordinated in accordance with signals received by the control mechanism  132  by a control system  460 , (not shown in FIG. 1, see FIG. 10).  
     [0030] One or more speakers  466  (not shown in FIG. 1; see FIG. 10) may be disposed behind the screens  116  and/or within the cabin  112 , as examples, although the speakers  466  may alternatively be placed in other locations. Sounds mimicking the sounds of an actual crane during operation may be produced over the speakers  466 , providing a realistic training environment, coordinated by the control system  460 .  
     [0031] A perspective view of the inside of the cabin  112  in accordance with the embodiment of FIG. 1 is shown in FIG. 2. An operator seated in the chair  134  is within easy reach of an optional steering mechanism or steering wheel  133  that is disposed in front of the chair  134 . A control mechanism  132  is also disposed proximate the chair  134 . The control mechanism  132  may comprise one or more controls, for example, including one of more of the following: rudders, handles, joysticks, or a combination thereof, disposed proximate the chair  134  within reach of the operator.  
     [0032] In the embodiment shown in FIG. 2, the control mechanism  132  comprises a left and right control panel  132   a / 132   b  disposed on the chair  134  armrests. The control mechanism  132  may alternatively comprise a single control panel, or two or more control panels placed proximate the chair  134 . If the actual crane the operator is being trained to operate includes a touch screen, an embodiment of the invention may include an optional touch screen  135 . For example, a touch screen  135  may be attached to one of the chair  134  armrests, for example, attached to the right armrest, as shown. Alternatively, the optional touch screen  135  may be disposed in other locations proximate the chair  134 . Preferably, the control mechanism  132 , steering mechanism  133 , and touch screen  135  are placed in the same location as in the actual crane the operator is being trained to operate.  
     [0033] The chair  134  may include one or more handles or controls (not shown) adapted to adjust the chair  134  for a plurality of parameters, such as height, seat and back angle, seat distance from back, for example, to provide the operator the opportunity to employ an ergonomically sound seating position. In one embodiment, the steering wheel  133  is part of a console (not shown) that includes a gas and brake pedal, such as in a simulator for a straddle carrier. The console may be mounted on the base  131  of the chair  134  to enable the operator to drive the crane.  
     [0034] The chair  134  is preferably mounted on a base  131 , such that the chair  134  may rotate on the base  131 . The steering wheel  133  and pedal console may be mounted on another rotating base disposed underneath the chair base  131  to provide for independent rotation of the steering wheel console and the chair  134 . The chair  134  may be rotated and locked in the following angles: −90 degrees, −45 degrees, 0 degrees, 45 degrees, and 90 degrees, as examples. The steering wheel  133  console is adapted to follow the chair  134  as it rotates. The steering wheel  133  is preferably attached to the chair  134  and is allowed to rotate up to 90 degrees to the side, to allow for a better front view when running the crane simulator  100 .  
     [0035] The control panels  132   a / 132   b  may comprise one or more of the following: joy-sticks, hydraulic or electric buttons, levers, alarm and indicator lights, as examples, to be described further herein with reference to FIG. 3.  
     [0036] The images projected on the screens  116  provide the perception to the operator that he is viewing a three-dimensional scene through the cabin windows  114 . Thus, the cabin simulation theater  100  comprises a virtual reality theater. On the screens  116 , the operator can view the boom or crane that seemingly extends from the equipment the cabin is associated with. The operator can view a hook or spreader (a claw-like object that is used to pick up objects) that is attached to the end of the boom. The operator can view objects such as containers and tanks that the operator is picking up and moving with the crane. The operator also has a view of the surroundings that the crane is simulating operation within.  
     [0037] The cabin  112  may be adapted to be moved to the left and right, and up and down by the suspended motion actuator  120 , according to how the operator manipulates the control panel  132 . The range of movement depends on the type of crane equipment the operator is being trained to operate. The images projected on the screens  116  are adapted to change in response to the operator&#39;s commands, made by moving the steering mechanism  133 , control panels  132   a / 132   b  and optional touch screen  135 . If the operator makes a mistake or bumps into something with the virtual reality crane shown in the images, the cabin  112  is moved by the motion actuator  120  so that the operator feels a realistic jolt or bump, for example.  
     [0038]FIG. 3 shows a left and right control panel  132   a / 132   b  in accordance with a preferred embodiment of the present invention. Preferably, the control panels  132   a / 132   b  are universal in design so that the cabin simulation theater  100  may be used for training on a variety of different styles and types of equipment. The cabin simulation theater  100  may be used for training on a high or low model container gantry crane, a straddle carrier, a portal or harbor crane, or a tower crane as examples.  
     EXAMPLE 1  
     [0039] Table 1 illustrates exemplary functions of the left control panel  132   a  when the cabin simulation theater  100  is used to train an operator in the operation of a container gantry crane.  
                       TABLE 1                       Device   Hardware   Description                  LD1 (Joystick)   2 axis, 5 button joystick           N       Trolley Fwd       S       Trolley Bwd       E       Crane Right       W       Crane Left       LD1 Left Button       Push and hold       N       List water side       S       List land side       E       Trim right       W       Trim left       NE       Skew right       NW       Skew left       SE       Skew right       SW       Skew left       LD1 Right Button       Selected flippers       Double-click       up/down       LA1   Buzzer   Buzzer       LA3   Push button momentary w/   Alarm (lamp/ack)           lamp, red       LB3   Push button momentary, black   Horn Silence       LA4   Lamp, white   Spreader landed       LB4   Lamp, white   Twin lift mode (detect)                  
 
     [0040] Table 2 illustrates exemplary functions of the right control panel  132   b  when the cabin simulation theater  100  is used as a container gantry crane.  
                       TABLE 2                       Device   Hardware   Description                  RA1 (Joystick)   2 axis, 5 button joystick           N       Lower       S       Hoist       E       W       RA1 Left Button       Twist locks       Double-click       lock/unlock       RA1 Right Button       Spare       RD1   Push button emergency stop   Gantry Crane               Emergency Stop       RD2   Key switch, 2 position   Start control system       RB3   Lamp, blue   Twist locks locked       RC3   Lamp, white   Twist locks unlocked       RD3   Push button latching w/lamp,   Power on/off           green       RD4   Push button latching w/lamp,   Rail brake on/off           red       RD5   Push button emergency stop   Simulator Emergency               Stop                  
 
     [0041] Tables 3-6 illustrate exemplary functions of the optional touch screen  135  when the cabin simulation theater  100  is used to train an operator in the operation of a container gantry crane, in various modes. A spreader screen (Table 3), boom screen (Table 4), crane screen (Table 5), and lights screen (Table 6) are depicted, although other screens may be available, such as alarm and messages screens, as example, for the various operations of the crane equipment.  
                   TABLE 3                       Functionality   Functionality                  Hydraulic pump on/off   Reset trim/list/skew position       20 ft select   Select left/right land-/waterside           flippers       40 ft select   Bypass 2 × 20 detection       45 ft select   Heavy load mode on/off       2 × 20 ft select       Over-height connect/disconnect   Head frame locked indication       Long twin adjustment in/out   Spreader cable connected indication       Store long twin adjustment   Twist locks locked/unlocked indica-           tion       Zero long twin setting   Spreader landed indication       Go to long twin memory position   Twin lift mode detection indication                  
 
     [0042]                           TABLE 4                                   Functionality   Functionality                                                Boom hoisting system on/off           Boom lift/lower           Boom stop           Enable override of boom/ship detection system           Override boom/ship collision detection interlock                        
     [0043]                   TABLE 5                       Functionality   Functionality                  Bypass crane/crane anti collision system   Another station on indication       Bypass sill beam anti collision system   Emergency stop on indication       Bypass wind speed   Trolley park position indication       Set trolley accelerations (normal, wet   Overload indication       rail . . . )       Anti-sway on/off   Crane stowed indication           Wind speed too high indication           Wind speed indication           Load indication           Hoist position           Trolley position                    
     [0044]                           TABLE 6                                   Functionality   Functionality                                                Lamp test           Floodlight trolley on/off           Floodlight portal on/off           Floodlight boom on/off                        
     EXAMPLE 2  
     [0045] Table 7 illustrates exemplary functions of the left control panel  132   a  when the cabin simulation theater  100  is used to train an operator in the operation of a straddle carrier crane.  
                       TABLE 7                       Device   Hardware   Description                  LD1 (Joystick)   2 axis, 5 button joystick           N       Shift left       S       Shift right       E       Shift fwd       W       Shift bwd       NE       Skew fwd ccw       NW       Skew bwd cw       SE       Skew fwd cw       SW       Skew bwd ccw       LD1 Left Button       Spare       LD1 Right Button       Spreader zero position       Double-click       LA1   Buzzer   Buzzer       LA3   Push button momentary w/   24 V indication           lamp, red       LB3   Push button momentary, black   Reset PLC       LA4   Lamp, white   Spare       LB4   Lamp, white   Spare                  
 
     [0046] Table 8 illustrates the functions of the right control panel  132   b  when the cabin simulation theater  100  is used to train an operator in the operation of a straddle carrier crane.  
                       TABLE 8                       Device   Hardware   Description                  RA1 (Joystick)   2 axis, 5 button joystick           N       Lower       S       Hoist       E       Drive direction fwd       W       Drive direction bwd       RA1 Left Button       Twist locks       Double-click       lock/unlock       RA1 Right button       20 ft/40 ft       Double-click       RD1   Push button emergency stop   Straddle Carrier               Emergency Stop       RD2   Key switch, 2 position   Start control system       RB3   Lamp, blue   Twist locks locked       RC3   Lamp, white   Twist locks unlocked       RD3   Push button latching w/lamp,   Diesel/power on/off           green       RD4   Push button latching w/lamp,   Park brake on/off           red       RD5   Push button emergency stop   Simulator Emergency               Stop                  
 
     [0047] The functions of the touch screen  135  when the cabin simulation theater  100  is used as a straddle carrier crane maybe similar to those shown in Tables 3-6, above, for example.  
     EXAMPLE 3  
     [0048] Table 9 illustrates the functions of the left control panel  132   a  when the cabin simulation theater  100  is used to train an operator in the operation of a portal or harbor crane.  
                       TABLE 9                       Device   Hardware   Description                  LD1 (Joystick)   2 axis, 5 button joystick           N       Boom lower       S       Boom hoist       E       Rotate cw/Drive right       W       Rotate ccw/Drive left       LD1 Left Button       Engage portal drive/       Double-click       LD1 Right Button       Spare       LA1   Buzzer   Buzzer       LA3   Push button momentary w/   Alarm (lamp/ack)           lamp, red       LB3   Push button momentary, black   Horn silence       LA4   Lamp, white   Portal drive engaged       LB4   Lamp, white   Spare                  
 
     [0049] Table 10 illustrates the functions of the right control panel  132   b  when the cabin simulation theater  100  is used to train an operator in the operation of a portal or harbor crane.  
                       TABLE 10                       Device   Hardware   Description                  RA1 (Joystick)   2 axis, 5 button joystick           N       Lower       S       Hoist       E       W       RA1 Left Button       RA1 Right button       RD1   Push button emergency stop   Portal Crane               Emergency Stop       RD2   Key switch, 2 position   Start control system       RB3   Lamp, blue   Spare       RC3   Lamp, white   Spare       RD3   Push button latching w/lamp,   Diesel/power on/off           green       RD4   Push button latching w/lamp,   Park brake on/off           red       RD5   Push button emergency stop   Simulator Emergency               Stop                  
 
     [0050] The functions of the touch screen  135  when the cabin simulation theater  100  is used as a portal or harbor crane may be similar to those shown in Tables 3-6, above, for example.  
     [0051] Other indicators, buttons, levers, and switches may be included on the control panels  132   a / 132   b . Spare positions for additional features are indicated by “SP” in FIG. 3.  
     [0052]FIG. 4 shows a perspective view of a motion actuator  120  in accordance with embodiments of the invention. The motion actuator  120  includes an upper attachment member  122 , a lower attachment member  124 , and a plurality of pistons  126  disposed therebetween. The upper attachment member  122  is preferably substantially triangular in shape, although alternatively, the upper attachment member  122  may comprise other shapes, such as circular or square, as examples. The upper attachment member  122  preferably comprises at least two brackets  140 , and more particularly, preferably comprises three brackets  140  for coupling the motion actuator  120  to the frame  118  (see FIG. 1). The brackets  140  may be coupled to the frame  118  using a plurality of screws and nuts, for example. Alternatively, other fastening mechanisms may be used to couple the motion actuator  120  to the frame  118  or directly to a ceiling, for example.  
     [0053] The motion actuator  120  preferably comprises a set of two pistons  126  coupled at a first end to each corner of a triangular-shaped upper attachment member  122 , as shown. The lower attachment member  124  is also preferably triangular in shape (although other shapes may be used), and one of the piston set  126  is coupled to one corner of the lower attachment member  124 , while the other of the piston set  126  is coupled to an adjacent corner of the lower attachment member  124 , as shown. Preferably, exactly six pistons  126  are coupled between the upper and lower attachment members  122 / 124 , although fewer or more pistons  126  may be used, for example.  
     [0054] The pistons  126  are preferably coupled to the upper and lower attachment members  122 / 124  by a bolt and nut, for example, although alternatively, other mechanical attachment devices may be used. Each piston  126  includes a motor  142  that is adapted to retract or extend the piston  126  to provide movement of the cabin  112 . In the motion actuator embodiment  120  shown in FIG. 4, the motors  142  are disposed on the lower portion of the pistons  126 , proximate the cabin  112  (not shown). This is advantageous because the lubricant used for the interface of the piston portion  136 / 138  will naturally flow downhill (e.g., towards the cabin  112 ) along the length of the pistons  126 , below the motors  142 . The upper and lower attachment members  122 / 124  preferably comprise steel, although alternatively, the upper and lower attachment members  122 / 124  may comprise other materials such as composite plastics or other metals, as examples. The pistons  126  preferably comprise stainless steel, and may alternatively comprise other corrosion-resistant materials such as titanium or other materials, as examples.  
     [0055]FIG. 5 shows a cross-sectional view of an embodiment of the motion actuator  120  wherein the motors  142  are disposed on the upper portion of the pistons  126 , proximate the frame  118 . The motors  142  are relatively heavy, and positioning the motors  142  above the pistons  126  decreases the amount of total weight that must be supported by the pistons  126  and motion actuator  120 . The pistons  126  comprise a fixed length portion  136  and a telescoping variable length portion  138  concentrically and moveably disposed within the fixed length portion  136 , as shown in FIG. 5. The motor  142  is adapted to retract or extend the telescoping variable length portion  138  according to commands received from the control system  460  (to be described further herein with reference to FIG. 10).  
     [0056] Referring again to FIG. 5, piston  126   a  is shown with telescoping portion  138  being partially extended, while piston  126   b  is fully retracted. By varying the piston  126  positioning in this manner, the motion actuator  120  is adapted to move portions of or the entire cabin  112  up and down relative to the frame  118 , which remains fixedly attached to the ceiling.  
     [0057] In one embodiment, the motion actuator  120  comprises exactly six pistons  126 . Alternatively, to save costs, the motion actuator  120  may comprise less than six pistons  126 ; for example, the motion actuator  120  may comprise exactly three pistons  126 . The motion actuator  120  may include an element adapted to turn the cabin, not shown. The turning element may comprise at least one roller and a motor to turn the roller, for example. The motion actuator  120  may also include one or more hydraulic power units (HPU&#39;s) adapted to move the pistons  126 .  
     [0058]FIG. 6 shows a perspective view of a cabin simulator theater  200  in accordance with another embodiment of the present invention, wherein a spherical screen  244  is disposed around a cabin  212 . Rather than having screens  116  disposed over windows  114  as described for the embodiment shown in FIG. 1, the windows  214  are either transparent or have the glass removed, so that the spherical screen  244  is completely within view of the operator. A portion of the operator viewing area is underneath or beneath the cabin  212 , for example, through a bottom window  214  or through a steep front window  214 . Because the back of the spherical screen  244  is open to allow the operator to enter the cabin  212 , the back window may include a screen  216  disposed thereon, with an image being projected thereon from the outside of the cabin  212 , for example.  
     [0059] The cabin  212  is suspended from a frame  218  or ceiling by a motion actuator  220 . The spherical screen  244  preferably comprises a translucent material such as canvas, glass or plastic, supported by a frame comprising aluminum or steel, as examples. The spherical screen  244  and frame may alternatively comprise other materials. A plurality of projectors  228  is adapted to project the simulator images onto the spherical screen  244  from the exterior of the cabin  212 , as shown. One or more speakers (not shown in FIG. 6; see FIG. 10) may be disposed behind the spherical screen  244  and/or within the cabin  212 , as examples, although speakers may alternatively be placed in other locations.  
     [0060] A perspective view of the back of the cabin simulation theater  200  of FIG. 6 is shown in FIG. 7. The spherical screen  244  may include a cut-out  246  in the back thereof, to allow entry of the operator into the cabin  212 . Optional stairs  248  may be disposed near the cabin  212  so that an operator may enter the suspended cabin  212 . Alternatively, the cabin  212  may be lowered (e.g. by fully extending the motion actuator  220  pistons) prior to the operator entering the cabin  212 . The frame  218  is also optional; alternatively, the motion actuator  220  may be fixedly attached directly to the ceiling of a room, for example. The cabin simulation theater  200  may be installed in a single room so that the lights may be darkened, for example, and so the operator will not be interrupted by external noises during use of the theater  200 .  
     [0061]FIG. 8 shows a back view of a cabin simulation theater  300  having a substantially opaque spherical screen  344  in accordance with an embodiment of the present invention, wherein a plurality of projectors  354  are disposed above the cabin  312 . The projectors are adapted to directly project images onto the spherical screen  344 , from the interior of the spherical screen  344  or the interior of the cabin  312 , or both, for example. The projectors  354  may be coupled directly to the upper attachment member  322 , as shown, or may alternatively be coupled to the frame  318 . Projectors  350  may be also disposed beneath the cabin  312 , adapted to project images onto the spherical screen  344  from the interior of the spherical screen  344 . The cut-out  346  in the back provides entry to the cabin simulation theater  300  by an operator.  
     [0062]FIG. 9 shows a perspective view of the spherical screen  344  in accordance with an embodiment of the present invention. In this embodiment, the dome screen  344  comprises a plurality of opaque, spherical-shaped screen sections  358 , comprising canvas, for example, although alternatively, other materials may be used. The spherical-shaped screen sections  358  are coupled together and are supported by a plurality of screen supports  356 , as shown. The screen supports  356  preferably comprise fiberglass, and may alternatively comprise aluminum, steel, wood, or other materials, as examples. The screen sections  358  preferably comprise polyester and may alternatively comprise polyester reinforced with fiberglass, or other types of cloth or other materials, as examples. For example, the screen sections  358  may comprise polyester stretched over fiberglass screen supports  356 , wherein the polyester screen sections  358  have fiberglass attached, e.g., welded or coated, to the polyester in some portions, to provide additional support to the dome screen  344  structure. The spherical screen  344  includes a cut-out  346  in back. The cabin  312  is suspended by a motion actuator (not shown) coupled to the screen supports  356 . A plurality of optional mirrors  368  may be used to deflect images from projectors (not shown) onto the interior of the opaque spherical screen  344 .  
     [0063]FIG. 10 illustrates a block diagram of a functional system  400  in accordance with embodiments of the present invention. A control system  460  may be coupled to a motion actuator  120 / 220 / 320 , a plurality of projectors  128 / 228 / 350 / 354 , optional speakers  466 , control mechanism  132 , and steering mechanism  133 , as shown. The control system  460  may comprise hardware  462  and software  464  adapted to control and coordinate the functions of the cabin motion simulator  400 . The control system  460  may also include memory  470  adapted to store one or more training programs, e.g., for various types of crane equipment. The functions of the cabin motion simulator  400  that are controlled and coordinated by the control system  460  include, but are not limited to: the mechanical movement of the motion actuator  120 / 220 / 320 , the projectors  128 / 228 / 350 / 354  that project visual images onto either the front of back of screens  116 ,  216 ,  244 / 344 , optional speakers  466  that may disposed anywhere in the room the cabin simulation theater is located in. The control system  460  is adapted to coordinate the operation of these elements in response to commands from the operator that are received by the control mechanism  132  and steering mechanism  133  that the operator is behind the controls of. Preferably, the images produced by the projectors  128 / 228 / 350 / 354  are digital, although, alternatively, analog images may be utilized in the cabin simulation theater  100 / 200 / 300 / 400 . The control system memory  470  may be adapted to store software programs and data, and may be adapted to store programs for the simulator  400  for one or more types of crane or other equipment.  
     [0064] An embodiment of the invention includes a method of manufacturing a virtual reality crane simulator. The method includes providing a cabin having a plurality of windows, the cabin being similar to an actual crane cabin, and suspending the cabin from a motion actuator. A screen is disposed proximate the windows, wherein the screen includes a viewing area that is underneath the cabin. The method includes providing a plurality of projectors adapted to project images onto the screen, attaching a chair to the cabin floor, installing a control mechanism proximate the chair, and coupling a control system to at least the motion actuator, projectors, and control mechanism, wherein the control system is adapted to coordinate the cabin movement and projector images in response to adjustments made to the control mechanism.  
     [0065] The simulators described herein may be used to train operators on a variety of hydraulic and mechanical crane equipment, as examples. While embodiments of the cabin simulation theater in accordance with the present invention are described herein with reference to crane simulators, they also have useful application in other simulators, such as for cranes used in the construction and petroleum industry, as examples. Other types of simulators would benefit from a cabin suspended by a motion actuator, as well.  
     [0066] Embodiments of the present invention provide an advanced crane simulator  100 / 200 / 300 / 400  with improved training effectiveness. When seated in the chair  134 / 234 , an operator has the sensation of operating an actual crane. While sitting in the cabin  112 / 212 / 312 , the operator may operate the control mechanism  132  and steering mechanism  133 , and feel movements, hear sounds, and view the surroundings as he would during the operation of a real crane. Thus, embodiments of the cabin simulation theater  100 / 200 / 300 / 400  provide a virtual reality crane simulator.  
     [0067] Embodiments of the present invention provide several advantages over prior art cabin simulation theaters. Unimpeded images on screens through the cabin  112 / 212 / 312  floor window or steep front window are visible to the operator because the cabin  112 / 212 / 312  is suspended from motion actuator  120 / 220 / 320 . The field of vision of the operator is increased with embodiments of the present invention, resulting in improved operation and safety training. In one embodiment, the piston motors  142  are disposed proximate the upper attachment member  122 , to reduce the weight load on the motion actuator  120 . Images may be projected either from the back side of the screens  116 / 244 , or alternatively, images may be projected from the front side of the screen  344 . Optional mirrors  130 / 368  may be used to deflect the projected images, or alternatively, the images may be projected directly onto screen  344 . The amount of time required to train on actual cranes may be decreased, by the use of embodiments  100 / 200 / 300 / 400  of the present invention.  
     [0068] While the invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications in combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. In addition, the order of process steps may be rearranged by one of ordinary skill in the art, yet still be within the scope of the present invention. It is therefore intended that the appended claims encompass any such modifications or embodiments. Moreover, the scope of embodiments of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.