Abstract:
Disclosed a virtual reality simulator for enabling a user to feel motion in virtual reality as the real. The virtual reality simulator comprises: a support frame; a disk plate provided over said support frame as distanced therefrom via a base plate; a lower plate rotatably coupled on said disk plate and having rotary means at one side thereof, an upper plate provided over said lower plate as distanced therefrom in a cooperative manner; a plurality of actuators hinged to the outer circumference of said upper plate and pivotal into the center and the outer circumference of said upper plate, each of said actuators being provided at an upper part with a piston and at a lower part with driving means for elevating said piston; a plurality of support plates pivotally provided on said pistons of the actuators via ball joints fixedly screwed into said pistons; and a shaking plate for supporting a chair at the top thereof for seating a user, said pistons penetrating said shaking plate and being coupled to upper parts of said support plates. The invention increases/decreases shaking of the chair to increase the reality, smoothly and rapidly carries out dynamic displacement and acceleration/deceleration of the chair, simplifies the structure of the actuators, and saves the manufacturing cost of the actuators to provide the simulator in a low price. The simulator smoothly accelerates and/or decelerates shaking of the chair to increase reality, and simplifies the actuator structure to save the manufacturing cost.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a simulator for experiencing virtual reality, and more particularly, to a virtual reality simulator which rotates and vertically shakes a chair which is coupled on the same as well as adopts crank-type actuators to increase/decrease shaking of the chair, thereby increasing the reality, smoothly and rapidly carrying out dynamic displacement and acceleration/deceleration of the chair, simplifying the structure of the actuators, and saving the manufacturing cost. 
     2. Description of the Related Art 
     As well known to those skilled in the art, a virtual reality simulator reproduces dynamic displacement according to virtual reality under the control of a computer so that a user may feel motion in the virtual reality as the real. Examples of the virtual reality simulator generally include chairs in game rooms and the like. 
     In such a virtual reality simulator, it is necessary to more vigorously vibrate a chair of the user to actively reproduce dynamic displacement so that the user of the virtual reality simulator can more actually feel the virtual reality. 
     For the purpose of realizing the above dynamic displacement, the simulator has adopted an actuator with a hydraulic cylinder or a pneumatic cylinder in the related art. However, in order to obtain the above simulator in which acceleration and deceleration are hardly controlled, an additional hydraulic cylinder or the pneumatic cylinder should be designed and manufactured. Then, the manufacturing cost of the actuator is increased as a drawback. 
     In order to solve the above problem, a proposal is made for a rack-and-pinion type actuator which is easily controlled in acceleration/deceleration. However, this type actuator has problems that shaking speed is too slow to realize rapid dynamic displacement and the manufacturing cost thereof is expensive. 
     SUMMARY OF THE INVENTION 
     Accordingly the present invention has been made to solve the foregoing problems and it is an object of the present invention to provide a simulator for experiencing virtual reality which has crank-type actuators so as to realize a simple structure, obtain rapid dynamic displacement and acceleration/deceleration, and reduce the manufacturing cost of the actuators thereby providing the simulator at a low price. 
     According to an aspect of the invention to obtain the above object, it is provided a simulator for experiencing virtual reality comprising: a support frame; a disk plate provided over said support frame as distanced therefrom via a base plate; a lower plate rotatably coupled on said disk plate and having rotary means at one side thereof; an upper plate provided over said lower plate as distanced therefrom in a cooperative manner; a plurality of actuators hinged to the outer circumference of said upper plate and pivotal into the center and the outer circumference of said upper plate, each of said actuators being provided at an upper part with a piston and at a lower part with driving means for elevating said piston; a plurality of support plates pivotally provided on said pistons of the actuators via ball joints fixedly screwed into said pistons; and a shaking plate for supporting a chair at the top thereof for seating a user, said pistons penetrating said shaking plate and being coupled to upper parts of said support plates. The invention increases/decreases shaking of the chair to increase the reality, smoothly and rapidly carries out dynamic displacement and acceleration/deceleration of the chair, simplifies the structure of the actuators, and saves the manufacturing cost of the actuators to provide the simulator in a low price. 
    
    
     BRIEF DESCRIPTION OF TIE DRAWINGS 
     The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings: 
     FIG. 1 is an assembled perspective view illustrating a simulator according to the invention; 
     FIG. 2 is a perspective view illustrating a driving unit of a simulator according to the invention; 
     FIG. 3 is an exploded perspective view illustrating a driving unit of a simulator according to the invention; 
     FIG. 4 is an exploded perspective view illustrating an actuator of a simulator according to the invention; 
     FIG. 5 is an assembled sectional view illustrating an actuator according to the invention; 
     FIG. 6 is a perspective view illustrating detection means of an actuator according to the invention; 
     FIG. 7 is a diagram illustrating the principle of a crank-type actuator according to the invention; and 
     FIG. 8 is a perspective view illustrating a simulator in use according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 to  8  show a virtual reality simulator  2  according to the invention which is generally comprised of a chair  10 , a driving unit  30  and a support frame  20 . 
     The support frame  20  for supporting the simulator  2  is provided in a place desired to install the simulator  2 . 
     Further, the driving unit  30  is provided over the support frame  20 , and the chair  10  is provided over the driving unit  30 . The chair  10  is adjustable in both of forward and backward directions according to the body of a user as typical sheet adjustment means in a vehicle, and has a computer in the front portion and a control lever at the side. 
     In the meantime, the driving unit  30  is provided on the support frame  20  to rotate and elevate the chair  10  for playing the same. 
     Further, the driving unit  30  is mainly comprised of a base plate  31 , a disk plate  32 , a lower plate  33 , rotary means  35 , an upper plate  36 , three actuators  40 , three driving means  70 , a shaking plate  39  and the like. 
     The base plate  31  is fixedly installed on the support frame  20 , and the disk plate  32  is provided on the base plate  31  as distanced therefrom at a certain distance. 
     Further, on the disk plate  32  is provided the lower plate  33  which is rotatably installed with a certain distance therefrom. A bearing (not shown) is preferably provided in a connecting section between the lower plate  33  and the disk plate  32 . 
     The above lower plate  33  is provided at the outer circumference with a plurality of recesses  34  which are so incised to avoid interruption from shaking of the actuator  40 , and the rotary means  35  is provided on the lower plate  33  at one side between the adjacent recesses  34 . 
     The rotary means  35  comprises a rotary motor  35   a,  which is rotatable forwardly and reversely, on the lower plate  33  and a roller  35   b  under the rotary motor  35   a.  The roller  35   b  is driven by the rotary motor  35   a,  and contacts to the outer circumference of the disk plate  32  so as to roll along the same. 
     In the meantime, the upper plate  36  is provided over the lower plate  33  as distanced therefrom via a plurality of rod members, and cooperates with the lower plate  33 . 
     The three actuators  40  are hinged to the outer circumference of the upper plate  36  as distanced from each other at 120 degree. The actuators  40  are controlled so that one or all of the actuators  40  are selectively operated. 
     Each of the actuators  40  has a housing  41  which is rotatably hinged at one side thereof to a hinge bracket  37  fixed to the upper plate  36  via a hinge pin  38 . The actuators  40  hinged like this are rotatable toward the center and the outer circumferential direction of the upper plate  36 . 
     In the meantime, the each actuator  40  is substantially quadrangular shaped and has the housing  41  for constituting the contour of the each actuator  40  so as to prevent exposure of the inside. 
     A piston  47  is provided on the each housing  41  to penetrate the same, and a support plate  48  is provided in the outer circumference of the outwardly penetrated piston  47  via screwed ball joint  48   a.  (Although three pistons  47  are shown in FIG. 3, description will be made in respect to one of them.) Over the support plate  48 , a lock nut  49  is screwed into a top portion of the piston  47  so as to prevent release of the support plate  48 . 
     Between the support plate  48  and the housing  41  is provided an elastic member  48   b,  which is inserted into the piston  47  and made of a compressive spring for alleviating impact due to rotation of the support plate  48 . 
     The elastic member  48   b  is preferably fixed at both ends thereof to the lower face of the support plate  48  and to the upper face of the housing  41 . 
     Further, a connecting rod  45  having a smaller end  45   b  and a larger end  45   a  is rotatably hinged to the lower end of the piston  47 , in which the upper smaller end  45   b  is inserted into the lower end of the piston  47  and rotatably hinged via a hinge pin  46 . 
     The hinge pin  46  has both ends inserted into guide grooves  41   a  longitudinally formed in both inner walls of the housing  41 , and is guided along the guide grooves  41   a  when the piston  47  and the connecting rod  45  are elevated so as to prevent eccentricity of the piston  47  and the connecting rod  45 . 
     Further, the lower larger end  45   a  of the connecting rod  45  is connected to a plurality of first and second crank cams  42  and  43  which are rotatably hinged to the housings  41 . 
     The crank cams  42  and  43  are eccentrically hinge to the larger end  45   a  of the connecting rod  45  via the hinge pin  44 . The second crank cam  43  is detachably coupled to each of the driving means  70  for elevating the piston  47  and the connecting rod  45  at an outer face of the housing  41 . On the other hand, the first crank cam  42  is connected to detection means  50  at another outer face of the housing  41 . 
     In the meantime, the each driving means  70  is comprised of a worm wheel  71 , a worm gear  74 , a driving motor  75  and a cooling fan  76 . 
     The worm wheel  71  is coupled to the second crank cam  43  at one side. A coupler  60  is formed integral with the second crank cam  43  at a central portion of one side of the second crank cam  43 . The coupler  60  outwardly penetrates from the housing  41  and has a groove  60   a  at one face. The worm wheel  71  corresponding to the coupler  60  has a coupler  73  cooperating with the worm wheel  71  via a connecting shaft  72  and having a projection  73  which is so shaped to be inserted into the groove  60   a  and coupled thereto. 
     Therefore, the each driving means  70  which is detached under repair or maintenance can be simply connected to each of the actuators  40  thereby improving the maintainability, assembling ability and workability thereof. 
     In the meantime, the worm wheel  71  has a gear section meshed into a worm gear  74 , which is connected to the driving motor  75  rotatable in forward and reverse directions for driving the worm gear  74 . Under the driving motor  75 , is provided the cooling fan  76  for outwardly radiating heat to prevent overheating of the driving motor  75 . 
     The worm wheel  71  and the worm gear  74  of the each driving means  70  configured as above are preferably mounted inside a gearbox. 
     Further, the detection means  50  functions for detecting the current condition of the shaking chair in order to simplify the initial installation of the actuator  40  and rapidly return the actuator  40  into the original position after actuation thereof. 
     The above detection means  50  detects the top and bottom dead points of the piston  47  and random position values in actuation via an encoder (not shown). 
     The detection means  50  is provided with a detection plate  51  which penetrates the housing  41  for cooperating with the first crank cam  42  at a central portion of one face of thereof. The detection plate  51  is provided with a stepped section  52  which is stepped from the outer circumference of the detection plate  51 . 
     Detection sensors  53  and  54  are provided in upper and lower portions of the housing  41  and distanced from the detection plate  51  to detect the stepped section  52  of the detection plate  51  rotating with the first crank cam  42 . 
     Although any of the detection sensors  53  and  54  may be used, the detection sensors  53  and  54  have leaf springs  53   a  and  54   a,  respectively, according to this embodiment. Switching of the detection sensors  53  and  54  is on when the round outer circumference of the detection plate  51  contact with the leaf springs  53   a  and  54   b,  and off when the stepped section  52  contacts with any of the leaf springs  53   a  and  54   b.    
     In the meantime, the shaking plate  39  for fixedly settling the chair  10  is arranged in the upper portion of the driving unit  30  having the above configuration 
     The shaking plate  39  has through-holes  39   a  which are perforated into the shaking plate  39  for receiving the pistons  47  of the actuators  40 , respectively. The pistons  47  of the actuators  40  are inserted into the shaking plate  39  via the through-holes  39   a  for fixing the shaking plate  39  to the support plates  48 . 
     Over the shaking plate  39  fixed as above is fixed the chair  10  via brackets. 
     In the meantime, the driving unit  30  configured as above is protected by a cover  30   a  defining the contour thereof and a bellows  30   b  contractible according to displacement of the chair  10  which shakes between the driving unit  30  and the shaking plate  39 . 
     Further, the actuator  40  of the invention converts a rotary motion into a linear motion as shown in FIG. 7, which illustrates the magnitude of stroke according to rotation of the crank cams  42  and  43 . 
     When the diameters of the crank cams  42  and  43  are equally divided into  16  parts, the angles are equivalently divided into 11.25 degree. However, there is a difference between constant acceleration/deceleration rates according to the position of each stroke distance according to rotation angle. 
     When the crank cams  42  and  43  carry out repetitive motion through forward and reverse rotation of 180 degree, the piston  47  and the connecting rod  45  move while drawing acceleration/deceleration circles as shown in the FIG.  7 . 
     The actuator  40  carries out acceleration/deceleration circular motion which is not performed by a conventional hydraulic or pneumatic cylinder or a rack-and-pinion type actuator. There are advantages that the actuator  40  is applicable at a lower price compared to a conventional actuator in a motion-based game machine in which precise numerical control is not required and thus a control program thereof is made simpler. 
     Further, the operation of the above simulator  2  is preferably controlled by a computer provided in the chair  10  or an additional controller via a regulator. 
     Further, the driving motors  75  and the rotary motor  35   a  are preferably made of servomotors. 
     Description will be made about the operation of the simulator  2  configured as above according to the invention as follows: When the rotary motor  35   a  provided on the lower plate  33  is driven, the roller  35   b  provided in the lower part of the rotary motor  35   a  rotates as contacting with the outer circumference of the disk plate  32  so that the driving unit  30  and the chair  10  of the simulator  2  rotates on the disk plate  32 . 
     The driving unit  30  and the chair  10  are rotated in forward and reverse directions via forward and reverse driving of the rotary motor  35   a,  and the lower plate  33  of the driving unit  30  is rotated on the disk plate  32 , in particular, smoothly by the bearing placed between the lower plate  33  and the disk plate  32 . 
     Further, the actuators  40  placed on the upper plate  36  of the simulator  2 , which rotates as above, vertically shake the shaking plate  39  and the chair  10  provided over the upper plate  36  with the each driving means  70  respectively provided at one sides of the actuators  40 . 
     In this case, the shaking plate  39  and the chair  10  vertically shake into various displacements as separately driven by their own actuators  40 . 
     In the meantime, when the driving motors  75  of the each driving means  70  rotatable in the forward and reverse directions are driven, the worm gears  74  at the upper ends of the driving motors  75  are rotationally driven. Then, rotation of the worm gears  74  rotationally drives the worm wheels  71  meshed into the worm gears  74 . 
     Then, the projections  73   a  of the couplers  73  integral with the connecting shafts  72  rotationally drive the second crank cams  43 , respectively, since the projections  73   a  are coupled to the grooves  60   a  of the couplers  60  which are integrally formed in the central portions of the second crank cams  43  at one sides of the actuators  40 . 
     The each crank cam  43  rotationally driven as above is driven in cooperation with the crank cam  42  provided in the opposite via the hinge pin  44 . Due to rotary driving of the crank cams  42  and  43 , the each connecting rod  45  with the lower larger end  45   a  being rotatably hinged to the hinge pin  44 , which connects between the both crank cams  42  and  43 , cooperatively converts rotary motion of the crank cams  42  and  43  into vertical reciprocating motion. 
     Due to the vertical reciprocating motion of the connecting rod  45 , the each piston  47  rotatably connected to the lower end  45   b  of the connecting rod  45  via the each hinge pin  46  carries out vertical reciprocating motion in cooperation with the connecting rod  45 . 
     In this case, the both ends of the each hinge pin  46  hinged to the smaller end  45   b  of the above connecting rod  45  are guided along the guide grooves  41   a  formed in the housing  41  of the each actuator  40  to perform stable vertical reciprocating motion thereby preventing eccentricity of the each connecting rod  45  and the each piston  47 . 
     Further, the vertical reciprocating motion of the pistons  47  enables vertical reciprocating motion of the shaking plate  39  fixedly coupled on the support plates  48  which are provided in the upper ends of the pistons  47  via the ball joints  48   a.    
     In the shaking plate  39  shaking as above, as shown in FIG. 8, driving one of the actuators  40  elevates the piston  47  provided in the driven actuator  40 . This raises the support plate  48  coupled to the upper end of the piston  47  via the ball joint  48   a  screwed thereto while tilts the support plate  48  on the ball joint  48   a  so as to incline the shaking plate  39 . 
     Therefore, the actuators  40  driven as above accelerates and/or decelerates the shaking plate  39  so that the shaking plate  39  draws various circles while shaking. 
     Further, when the shaking plate  48  is driven as tilted as above, the elastic members  48   b  made of the compressive springs between the support plates  48  and the housings  41  alleviate impact due to load applied from the chair  10 . 
     In the meantime, the actuators  40  are angled at 120 degree from one another on the upper plate  36  and rotatably hinged on the hinge brackets  37  of the upper plate  36  via the hinge pins  38 . When at least one of the actuators  40  is simultaneously driven, the actuator  40  is rotated toward the central portion or the outer circumference of the upper plate  36  to further compensate the angle of the shaking plate  39  which is shaking while making various displacements by the support plates. Then, motion of the chair  10  is more dynamically reproduced. 
     In other words, the each driving means  70  is controlled according to a program inputted into a computer or an additional controller to selectively drive at least one actuator  40  as well as the driving means  70  is driven to variously change the position of the chair  10  in three-dimensional spatial coordinates so that motion in the virtual reality can be dynamically reproduced. 
     In the meantime, a current driving condition of the each actuator  40  driven as above is detected by the each detection means  50  which is provided in one side thereof, and then inputted into the computer or controller. 
     This means that the leaf springs  53   a  and  54   a  of the detection sensors  53  and  54 , which are distanced from each other over and under the detection plate  51  of the detection means  50 , contact with the outer circumference of the detection plate  50  when the detection plate  51  rotates together with the crank cam  42 . When the leaf springs  53   a  and  54   a  of the detection sensors  53  and  54  contact with two points in the outer circumference of the detection plate  51 , contacts of the detection sensors  53  and  54  are on. When any of the leaf springs  53   a  and  54   a  of the detection sensors  53  and  54  contacts with the stepped section  53  of the detection plate  51 , the contacts of the detection sensors  53  and the  54  are off. Although not shown, a random value of the stepped section  52  is detected by an encoder. 
     Therefore, in the actuators  40  for shaking the shaking plate  39  and the chair  10 , the pistons  47  and the connecting rods are positioned in the bottom dead points by means of controlling the driving means  70  with the detection means  50  after the simulator  2  is driven. 
     According to the virtual reality simulator of the invention as described hereinbefore, the crank-type actuators are adopted to increase/decrease shaking of the chair thereby increasing the reality, smoothly and rapidly carrying out dynamic displacement and acceleration/deceleration of the chair and simplifying the structure of the actuators. The manufacturing cost of the actuators is saved so that the simulator can be provided at a low price.