GB2154146A - Ball game simulation apparatus - Google Patents

Abstract

The apparatus for simulating a a game, e.g. golf, comprises a screen 18, on which an image from a picture store is displayed, measuring devices in planes 14 and 15 coupled to a computer control unit 16 to determine the trajectory of a ball when hit, and means to display a moving ball image on the screen corresponding to the calculated trajectory. A video tape or disc may store information and images of a golf course and provide a view to the green from each new ball position together with information on distance to the hole. <IMAGE>

Description

SPECIFICATION Ball game simulation apparatus This invention relates to apparatus for simulating a ball game, and it is especially applicable to simulating the game of golf, although it can be used for other games such as soccer. The apparatus is useful for training and practice purposes, or purely as a recreational activity.

The present invention provides a ball game simulation apparatus, comprising a screen adapted for displaying an image; storage means arranged for storing picture information relating to a playing area and for displaying an image of the playing area on the screen; sensing means arranged to sense the trajectory of a ball when hit; and calculation means arranged to receive an input from the sensing means, to calculate therefrom a ball position in relation to the playing area, and to output a signal to the screen which superimposes a ball image on the image of the playing area at said ball position.

Preferably the calculation means calculates the path of the ball in relation to the playing area, and superimposes a moving ball image on the image of the playing area, representing the ball path.

In order that the invention may be more clearly understood, a preferred embodiment of a golf simulation apparatus will be described, purely by way of example, having reference to the accompanying drawings, wherein: Figure 1 shows the general schematic arrangement of the apparatus, Figure 2 is a block diagram of the apparatus, Figures 3,4 and 5 are geometrical diagrams for explaining the calculation of ball path, Figure 6 is a further geometrical diagram showing how a ball position in a playing area may be calculated, Figure 7shows a screen display, and Figures 8 and 9 are geometrical diagrams explaining the screen display.

The simulation apparatus shown in the drawings is particularly intended for serious training and practice of the game of golf. However, it will be appreciated that it can be used purely as a game if desired, and that it can be adapted to simulate other ball games, e.g. soccer.

The apparatus can be used by one or more players at a time.

The primary function of this trainer is to enable improvement of golf skills at home in a limited space. A practice ball is played with the normal range of clubs from a tee 10 into a net 12. Measuring devices in planes indicated by lines 14,15 in Figure 1 are coupled to a computer control unit 16 and determine the velocity of the ball and the rate and orientation of spin. A picture of a golf green viewed from the tee is displayed on a television screen 18. The computer calculates the position of the ball on the course as if a real golf ball had been played, the computer having been programmed from actual live tests, and the ball simulation is shown superimposed on the screen at the position calculated.For the next stroke, a button on a control console 17 (Figure 2) is pressed giving a view to the green from the new position and the range, and so on until the final putt of a few feet into a hole on the machine. The next hole is then played, a video tape or disc within the control unit storing all the information of eighteen holes of an actual course including positions of bunkers.

The ball is played into the net from the tee, or from artificial grasses to simulate fairway or rough (see Figure 1). For final putting shots of short length, the ball is directed at an enclosure or hole on the floor. The elevation and direction of the ball's path are measured at the planes 14,15 by sensors 20 (Figure 2), by the interruption of beams (infra-red, visible light, laser, ultrasonic or radar). Speed is measured by the time taken to pass both planes. The sensors can also detect the ball elevation and direction, and all this information is fed to the computer 22 in the control unit 16, via an analyser 24.

If desired, the ball may have metal contacts and a transmitter 26 which send a signal to a receiver 28 in the control unit when the ball is struck at a particular position. The ball has reference lines on its surface to position it correctly on the tee relative to line of flight. The computer can then determine the rate and orientation of ball spin. This is described below in relation to Figures 4 and 5.

A video tape or disc unit 30 programmes the computer 22 on the distance to each hole from the tee, the shape of the fairway and the position and size of bunkers. The video unit 30 displays a view of the green from the tee orfairway directly on the screen 18, and this image has superimposed information such as hole number and distance to hole, provided from the computer 22. The fairway is mapped out on a grid of coordinates, the tape or disc storing the view to the green from each coordinate position, each grid square being a fixed size (see Figure 6 and the discussion below on geometry). The computer would identify if the ball was in bunker, and then a ball flight elevation of above a minimum value would be required to escape, simulating actual play.The initial position of the simulated ball travel across the screen would be determined from the direct measurement of ball flight direction, and superimposed on the screen 18 via processing circuitry 32. Any adverse computed spin resulting from a hook or slice shot would give an arc of travel, the ball coming to rest at the computed position on the screen. (See Figure 7.) Typical trainer controls required would include possible allowance for wind, cancelling a stroke and displaying the score table on the screen.

Referring to Figure 3, from the standard equations of motion for a projectile, z = (v0sin60)t - 1/2gut2 and x = (v0cos60)t To determine the theoretical range RTH, then z = 0 Therefore (vOsinHO) t = gut2 t = 2vOsin0O 9 RTH = 2VO2 sin00cos()0 9 Actual travel of ball is shortened by air resistance

where K is an unknown constant or variable The computer 22 is programmed to determine the ball path from these formulae, and to display the ball image in the correct positions on the screen 18.

Golf ball travel is further influenced by its spin, i.e. hook, slice, topspin and backspin.

In Figure 4 if ball is struck below the plane at angle 0a then there will be induced backspin, the larger angle 62 the greater the spin speed. Similarly, if the ball is struck above the plane at angle 6o, then there will be induced topspin. In Figure 5, the contact point relative to direction of travel 6, produces a slice as shown, a hook being produced if the point of contact is to the right of plane 0,. Knowing the approximate point of contact on the ball, from the transmitter 26, the spin effect, if any, can be estimated by the computer and used to modify the displayed ball path.

The computer can be programmed from actual tests on an outdoor range with proper golf balls to determine the value of K and the effect of spin. An allowance can thus also be determined for the fact that the position of the placed ball is not at the true origin of the flight elevation path, the ball being carried along the arc of travel of the club for a short distance.

The component values of the ball velocity measurements are fed from the machine into the computer, and the exact coordinates of the calculated ball position are rounded up to the nearest coordinate position. This is shown in Figure 6, where position A is +4, -2, for example.

For the next stroke, the screen displays the view from point A to the hole and the distance thereto.

The process is repeated to position B, say, and then to the hole.

The method to calculate the respective coordinate positions is simple geometry.

Figures 7 to 9 show the calculation and display of a ball in flight. The angles , and 42 in the elevation of Figure 8 and plan of Figure 9 are calculated, the angles that are subtended by the eye in viewing the ball. The ball position on the screen is thus determined as shown in Figure 7.

Claims (1)

1. A ball game simulation apparatus, comprising a screen adapted for displaying an image; storage means arranged for storing picture information relating to an actual playing area and for displaying an image of the playing area on the screen; sensing means arranged to sense the trajectory of a ball when hit; and calculation means arranged to receive an input from the sensing means, to calculate therefrom a ball position in relation to the playing area, and to output a signal to the screen which superimposes a ball image on the image of the playing area at said ball position.

Preferably the calculation means calculates the path of the ball in relation to the playing area, and superimposes a moving ball image on the image of the playing area, representing the ball path.