Tenpin bowling is played on a wooden lane or one of synthetic material, according to the specifications of the American Bowling Club ABC/WIBC. 10 pins are positioned at one end of the lane while the player throws a ball from the other end in the attempt to knockdown as many pins as possible. Please refer to the ABC/WIBC specifications for the complete set of game rules, as this is merely a generic description. There are many types of games, which differ in the number of pins, shape, positions, score rules, shape and dimensions of the lanes, balls and pins; here are the most popular: 10 pin, 9 pin, candle pin, 5 pin, figure, duck pin, red pin. The wooden lane is rectangular, 19 meters long and 3 meters wide and the pins are positioned on top of it. The game is played on the lane, which consists in throwing bowling balls towards the pins in the attempt to knockdown as many pins possible. The pin deck is the minimum square area on which all the pins are positioned (9). In the case of tenpin bowling, the pins are positioned in the shape of a triangle. Pin 1 is the pin at the head of the triangle. The player or bowler is the person who throws the ball in the attempt to knock down the pins. The game of bowling is played between one or more bowlers and has the purpose of scoring the highest number of pins knocked down in a certain number of throws. For example, in the case of tenpin bowling, each game is split-up into 10 frames. One frame is a combination of two throws. The bowler throws the ball from the bowling deck: from the opposite end to where the pins are positioned. The bowler must not step over the foul line, which is 18 meters away from the pins. A bowler is said to have committed a foul if he steps over the foul line when throwing the ball. Hdcp is a bonus starting score assigned to a less expert player in order to make the game fair. The ball return (17) (23) is a mechanical device that returns the ball back to the same bowler so that he can make his next throw. The platform where the ball falls (21) is the lower part of the lane; its purpose is that of blocking and holding the ball thrown; it is set at a slant so that the ball, through the mere force of gravity, rolls towards the inlet of the ball return pit, through which the ball is returned to the beginning of the lane. It is situated at the opposite end of the lane compared to the deck where the ball is thrown. The mechanical pinsetter is an automatic system that puts the real pins knocked down back in place after each throw. Mechanical pinsetters channel, move, turn and therefore position the real pins in established positions exploiting mechanical systems. The lane area in which the pins are positioned by the mechanical pinsetters is marked specifically to point out the exact position of the pins. An animation is a sequence of static pictures that give the human eye the impression of moving objects. These pictures are sequentially projected against a screen at a speed of more than 25 pictures per second and differ from one another by slight movements in the objects contained within the pictures. The perspective view is the point in space from which we get the impression of depth of objects contained within a picture, when looking at a picture produced with the laws of perspective. The physical simulator is a computer that exploits the axioms, theorems and formulae of mechanics. It displays a perspective animation in real time on a screen. This animation has the fundamental feature of reproducing the behavior of objects in the real world according to the laws of nature. This simulator receives information from the real world through sensors that measure the speed, position and mass of real objects. With this information it then simulates the behavior of objects that in reality do not exist but that interact with the real objects. The combination of the real objects and the unreal objects is displayed on the screen with the dynamic behaviour and sounds that they would have if they were all real. The holographic pinsetter is a physical simulator that gives human beings the illusion of the presence of pins. It simulates the behaviour and the interaction of the virtual objects with the real objects, such as the ball and the lane. This means that the holographic pinsetter does not need all the mechanical parts, which make mechanical pinsetters the systems most susceptible to wear, slower, expensive, unstable, cumbersome, heavy and generally less efficient. The holographic screen is made of transparent material, which when hit by the light of a projector, diffuses the light semi-spherically, thus covering the light that crosses it. The effect perceived by the onlooker is that the pictures projected are seen on top of the real pictures produced by the light reflected by the bodies of the real objects. A reflecting screen reflects the light sent from a luminous source, such as a projector, but does not let the light through. The arrows (69) are drawn in the centre of the lane at a few meters from the foul line in certain positions and act as reference marks for the bowler. There are some black spots (47) on the lane that point out the exact position in which the pins are to be positioned. The visual angles of a video camera are the angles where all the objects within the two half-lines of the angle can be seen in the picture generated by the camera.
When a mechanical pinsetter is faulty, the operator commands the control unit (15) (33) using a keyboard and instructs it to change the faulty lane. The control unit (15) (33) starts the motor (34) that moves the holographic pinsetter, commencing by moving the dolly (40) (6) (66) to which elements (1) (2) (3) (4) (5) (7) (8) (19) (24) (25) of the holographic pinsetter are connected. The control unit (15) (33) of the dolly starts to verify the position of the dolly (40) (6) (66) by reading the information sent to it by the position sensor (60), fitted on the tracks (63) (44) (77). The control unit (15) (33) counts the inputs sent from the sensor (60) and, considering that each lane has one, it is capable of deducing on which lane it is situated. Once it detects that the dolly has reached the position required, it stops sending the input that operates the motor (34) of the dolly (66) (40) (6).
When reading the first and the last lane, the sensor receives a double input, considering that the reflex reflector (61) consists of two reflex reflectors separated by a small non-reflecting gap. In this way, the control unit (15) (33) realises whether it is at the end or the beginning of the tracks. At this stage, the control unit (15)(33) sends an electrical signal to the control unit of the holographic pinsetter (8)(43) to instruct it to start the simulation. The above-mentioned transport system may not be installed and, if this is the case, each lane has a holographic pinsetter and the functions performed by the control unit (15) (33) and described in this report, are carried out by control units (8) and (43). This solution offers a few advantages: it is quicker, since there is no need to transport it to the lane required, in which case the costs are naturally higher.
The projector (5) starts to display the animated sequence of the pins and the bowler (18) gets the impression that the pins are actually on the pin deck (9).
The control unit (8) (43) continuously receives the pictures sent from the camera (1) and exploits them to change the perspective view of the animated sequence sent to the projector (5). In this way the bowler (18) standing on the lane, always has a perfect view of the pins, considering that it is that nearest to reality: this is achieved thanks to the fact that the perspective view of the projected picture is modified based on the position of the bowler's eyes. The control unit (8) (43) has a three-dimensional mathematical model of the position and direction of the lane, of all the sensors, of the screen and of all the objects involved in the simulation. It stores the dimensions and positions relative to all the parts making up a lane and their physical properties according to the ABC/WIBC specifications. The known properties of the balls for example, are the weight, the moment of inertia, the dimensions, the mass, the elasticity, the friction, the three-dimensional model, the positions and the directions in space. The pictures received from the video cameras (1) (3) are related mathematically to projections on a flat square surface, which corresponds to the three-dimensional model of the video cameras; through the identification in the projected pictures of at least 4 coplanar points known in the three-dimensional model, we can determine an unmistakeable association between the pictures and the three-dimensional model used in the simulation and therefore we can deduce the position, the direction and the inclination of the video cameras, of which we also know the optical characteristics, such as their visual angles. We can therefore determine an area of the picture, which corresponds to the deck where the ball is bowled, of which the significant chromatic variations are verified in order to identify the body of the bowler and his position in space. This is done by associating the chromatic variations with mathematical methods of probabilistic identification of the silhouette of the bowler. Simplifying principles are also assumed and, considering that we know the direction of the camera, we can deduce that the chromatic variations in the top part of the pictures relate to the upper body of the bowler and vice versa for the bottom part of the chromatic variations. The 4 points are determined by finding the foul line (70), the arrows on the lane (69) and the edgings (49) of the lane or by arranging coloured spots (46) (48) on the edges of the lane at fixed and known distances/positions. The control unit (8)(43) also controls the portion of picture corresponding to the adjacent area around the foul line and can establish if the bowler steps over the foul line (70) while throwing the ball: in other words, if any significant chromatic variations are detected, the event is saved and taken into consideration when calculating the score displayed on the screen (19) and saved in the unit (15) and (8). The chromatic variations must have a sufficiently long duration and be measured experimentally to be associated with the bowler's foot, otherwise they are associated with the ball passing the line as it is thrown.
The bowler starts to throw the ball towards the pins, which are projected on the holographic screen (19). Remember that the bowler only has the impression of seeing real pins on the pin deck (9).
The animated sequence produced takes into consideration some objects, such as the ball (11), which are set over the pins; where the animation takes place, space is left for the real objects, by not projecting the virtual objects. When the ball passes under the screen (19), the RF reader (4) receives information sent to it in radio frequency by the ball (11) and this information is then sent from the RF reader (4) to the control unit of the pinsetter (8)(43).
From here on the ball enters the visual range of the camera (3) and the control unit (8) exploits the pictures sent from the camera (3) to determine when the ball has rolled passed, calculating its speed, its trajectory, its dimensions and its angular speed. These measurements can only be achieved on a picture if there is a three-dimensional model and its relation with the pictures of the camera.
To obtain this relation, at least 4 known and coplanar points in the three-dimensional model must be identified on the two-dimensional pictures. To do this, the control unit (8) analyses the pictures and determines the gutters (50) (49) and the position of the 10 spots (47) that point out the position of the pins on the pin deck or 4 additional coloured spots (48) arranged on the edges of the lane at fixed and known distances. If the control unit (8) fails to identify the 4 optional coloured spots (48), it determines the 4 coplanar points with the 10 spots (47) and the edges of the lane (49) present on each lane. The angular speed for balls without gyroscopic sensors is determined by analysing the superficial movements of the ball, which can be enhanced for plain coloured balls by using at least 6 spots of different colours arranged on the ball surface and positioned so that at least one is always visible. The Spots are stuck to the surface of the ball and are crossed by 3 non-coinciding straight lines, arranged perpendicular to each other. The 3 straight lines meet in the geometrical centre of the ball. These movements are then reproduced in the three-dimensional model as projections, on the optical surface of the camera, of spots on the spherical surface of the ball positioned on the lane deck. In this way we can determine the angular speed of the ball with mathematical precision, using formulae of geometry, perspective and of classical physics. The control unit (8) receives all this information and processes it with the mathematical models of mechanics. It starts sending the signal that will show the simulation of the ball striking the pins to the projector (5). As the ball reaches the pin deck (9), the control unit (8) displays the pins colliding against the ball (72) (73) (74) (75) and starts to move them as if they were moving in reality.
The union in the animated sequence of the real ball and the virtual pins, and all this in real time, produces a visual effect that gives the bowler the impression of playing with physically real pins, as seen in
In
You can also use non-transparent reflecting screens if you want to hide everything situated on the other side; this means that the animated sequence will also show objects covered by the screen, such as the ball and lane. In this case, all the colours of the ball and of the lane are captured by the pictures taken by the video camera (3) and are reproduced in the virtual sequence on the screen (19).
The real ball will then hit the end of the lane (12) (37) and, thanks to the slanted platform at the end (21), it will fall through the outlet hole (13). Its diameter will then be measured by the dimensional measuring unit (26) (39) and finally it will be weighed again by the weight sensor (14), of which there is one for the pair of lanes. This sensor will send the information to the control unit (15) (33) of the tracks (44) (63), which will then send this information to the control unit (8) (43) of the holographic pinsetter (
To be pointed out is the fact that the ball stopping cushion (12) is equipped with a movement sensor (27) that measures the quantity of motion absorbed each time it is hit by the ball. It then sends this information to the control unit (8), which is aware of the known, determined and constant physical parameters of the cushion (12) and is capable of calculating the weight of the ball that hit it. Considering however that the weight and dimensions of the ball are measured after the ball reaches the end of the lane (12) this information is registered by the control unit (8) and utilised the next time the bowler throws his ball again. We therefore assume that all bowlers tend to use balls of the same weight and dimensions. This means that the system must have the list of bowlers and keep track of their score to be able to foresee whose turn it is to play and to be able to save the dynamic information of the balls used by each bowler; this information is entered either on the console (16) or the keyboard of the control unit (15) at the beginning of each game. The dimensions of the ball are also determined through a perspective calculation, using the pictures of the camera (3) and the three-dimensional model described previously.
Later, the ball will be returned to the bowler by the ball return (17) and the control unit (8) will show the pins still standing. The bowler can make his next throw, which will cause the repetition of the events in the sequence just described.
Considering that the main feature of the holographic pinsetter (
The part of holographic pinsetter made up of elements (8) (6) (7) (23) (1) (2) (3) (4) (5) is covered and concealed behind the false ceiling (22), which has a triangular shape and hides the equipment away from the bowler's sight (video cameras (1) (3), control unit (8) and transport tracks (7) etc. Considering that the screen (19) and the supports that connect it to the dolly (6) are transparent, the bowler doesn't really see them.
The holographic screen (108) must remain a few meters away from the end of the lane and must remain suspended from the ground to leave enough room so that no interference is created with the ball (103) as it rolls along the lane. This distance from the pin set-up causes a perspective error that we can correct using the camera (1) that observes the bowler. To avoid this correction we can use a screen, as seen in (118) (119), where the picture is projected on the screen that touches the lane (120). The bottom part of this screen has some mobile elements (119) (115) so that when the ball (116) touches them they raise (111) (112) to let the ball through and return to their original position (115) as soon as the ball has reached the other side. In this way we can project the pins in their original position, thus minimising the perspective error.
This mobile part consists of reflecting flaps (119) that are; secured to the rigid screen (114). Their special feature is that they are mobile (112) or flexible (115) and have the same properties as a screen. To prevent the flaps from being hit by the ball and becoming dirty, we can lift them before the ball actually hits them (112) by installing a piston (113) that raises the flap. The piston is controlled by the control unit (8), which determines via camera (3), where the ball will hit the flaps (119); each flap has a piston (113) that is independently controlled by the control unit (8). Another variant is that of projecting also the picture on the lane using an additional screen (104). In this way the perspective error is reduced and the flaps eliminated (119). A curved screen (121) is added at the end of the lane to improve the perspective view. The transparent screen (101) is placed above the pin deck instead of a few meters away from it, as in position (108).
In this case there are two reflecting screens, one at the end of the lane (104), on the pin deck, and one in position (101). The picture projected by the projector (102) must be such to give the observer (106) the impression of seeing real pins on the pin deck. The two pictures projected on the screens (104) (101) are composed by the bowler's eyes (f. 7.6) because he has the impression that the pins are real.
The light (84) emitted by an external source (81) reaches the screen and passes through it without being reflected (85); in this way the screen does not reflect the light of objects that are not involved in the simulation. The light (86) sent from the projector (83) is diffused towards the observer, as can be seen in (87), so that the system can display objects that the observer perceives to be behind the screen. This realistic sensation is improved through a perspective correction of the objects projected, which is done in real time, considering that we identify the variations in position of the perspective point, which in our case is the bowler's eye.
As described below.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IT05/00116 | 3/2/2005 | WO | 00 | 8/26/2007 |