APPARATUS FOR DEFINING THE SPEED AND DIRECTION OF A BOWLING BALL
The present invention relates to an apparatus for defi¬ ning the speed and direction of a bowling ball, the said apparatus comprising a suitable detector, for example a TV-camera or equivalent, a calculator unit, for exam¬ ple a microprocessor, as well as a display unit for pro¬ ducing the output in order to observe the speed and di¬ rection and/or deviation from direction of each bowling ball.
In bowling, success in competitions and good results in general depend completely on the rolling performance, which should be repeated in similar fashion roll after roll. Such repetition in the rolling performance can be learned only by training and industrious excercise.
According to modern methods of training for bowling, the best rolling technique is such that the ball is rolled through certain aiming arrows located at the beginning of the bowling lane, without viewing the set of pins at all. In this case training does not necessarily requi¬ re a full-length bowling lane of 18,3 meters, but a re¬ markably shorter lane is sufficient - roughly about 5 meters long. This shorter lane is provided with aiming arrows and includes a ball return machinery. The set of pins is not necessary when training.
In a conventional bowling alley the bowler can estimate the accuracy of his rolls judging by the amount of dis¬ posed pins. In training, however, this is not suffici¬ ent, because the exact path of the ball cannot be dedu¬ ced from the result. The only way for the bowler to check whether the ball passes through the desired ai¬ ming arrows is to use his own eyesight.
In prior art' are known several suggestions for devices for defining the path or direction and speed of a bowl¬ ing ball. The US Patent Publication No. 3,252,705 intro¬ duces an apparatus for illustrating the bowling ball path on a TV-screen. The equipment for measuring the position of the bowling ball comprises metal wires loca¬ ted at both sides of the lane. The ball causes inter¬ ference in the electric field created between these me¬ tal wires. The dielectric properties of the ball are naturally different from those of the surrounding air, and as the ball deviates from the center line of the lane, an unbalance is created in the electric field. The position of the ball can also be defined by using other methods, for example by utilizing weak radioacti¬ ve radiation within the ball.
The measuring results are produced on a screen, which shows the relative movement of the ball along the lane. The picture remains permanently visible, so that the trainee has sufficient time for studying his performan¬ ce in the display unit.
The US Patent Publication No. 3,051,485 describes an apparatus for defining the rolling direction of a bowl¬ ing ball. The said apparatus comprises a training lane shorter than a normal bowling lane and a detector con¬ nected to the lane in order to define the transverse po¬ sition of the ball. The detector is constructed of se¬ veral pairs of illuminators and photocells, which are located in succession along the width of the lane. When the ball passes through a certain pair, light is reflected from the ball to the photocell. The appara¬ tus is designed so that the bowler can choose a certain point on the lane, through which point he wants to di¬ rect his ball. Now only the photocell which is located at the desired point is in function. If the ball pas¬ ses the said point, the apparatus gives a suitable sig-
nal .
The US Patent Publication No. 3,145,025 introduces an apparatus for definining the speed of a bowling ball. The apparatus includes two beams of light, which beams are directed across the bowling lane at a suitable dis¬ tance from each other. As the ball cuts the first beam of light,. it switches on a calculator which counts pulses at the speed of 120/s. When the ball cuts the second beam of light, the calculator is switch¬ ed off. Thus it is possible to find out how much time the ball has' used between the two beams of light, and further to estimate the average speed of the ball.
There are several drawbacks in the apparatuses descri¬ bed above. The apparatus of the US Patent Publication No. 3,252,705 can be used only in connection with full- length bowling lanes. The obtained results are some¬ what vague, because by using the said apparatus it is very difficult to compare the similarity of successive rolls. The apparatus does not define the speed of the ball nor its starting direction accurately enough. However, the best way to follow the development of one's skills is to compare the said quantities in successive rolls and to observe their relative similarity.
The apparatus presented in the US Patent Publication No. 3,051,485 measures the position of the ball in the trans¬ verse direction of the lane, but only at one point. The apparatus of the US Patent Publication No. 3,145,025 mea¬ sures only the speed of the ball.
The purpose of the present invention is to achieve an apparatus which measures both the speed and direction and/or deviation from desired direction of the ball. A further object of the present invention is to realize a measuring apparatus which can be connected to any oιv__ "
existing bowling lane as a training device or attached to a short training lane. In order to realize this, the apparatus of the invention is characterized by the novel features which are mainly enlisted in the novel part of the Patent Claim 1.
The operation of the apparatus is based on the fact that the* black bowling ball forms a sufficient contrast in comparison with the white bowling lane. Thus in the video signal received from the TV-camera, the ball has a negative pulse which is clearly different from the white background of the video signal. The form of the object - a ball - is highly advantageous for detection, because it can be seen in similar shape from a suffi¬ ciently wide angle.
The vertical, i.e. the y-coordinate of a bowling ball in the TV-screen is obtained by counting the number of the line synchronizing pulses or line pulses which oc¬ cur after the field blanking pulses or field pulses, but before the pulses received from the ball. The horizon¬ tal, i.e. the x-coordinate of the ball is obtained by counting the cycles of a high-frequency oscillator between the line pulse of the ball -occurrence line and the pulse representing the ball. The frequency of the high-frequency oscillator is chosen so that the condi¬ tions for the accuracy of the apparatus can be fulfil¬ led.
As the most outstanding advantage of the apparatus can be mentioned the fact that the trainee receives immedia¬ tely and in digital form the information concerning the speed, direction and/or deviation from direction of each roll. Further advantages are the reasonable prize of the apparatus and its adaptability for various different bowling lanes.
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In the following the invention is described in further detail with reference to the appended drawings.
Figure 1 is a schematical illustration of the apparatus according to the invention, as connected to a trai¬ ning lane.
Figure 2 is a schematical illustration of the block dia¬ gram of the apparatus of the invention and its cou¬ pling arrangements.
Figure 3 is an illustration of the unit for sorting out the visual information.
Figure 4 is an illustration of the visual field of the bowling lane covered by the TV-camera.
According to Figure 1 , the TV-camera 1 functioning as a detector is located above the training lane 2. The training alley includes a normal approach lane 3 and thereafter a relatively short lane 4. At the end of the lane 4 there is placed a retarder device 5 and a buffer 6, which buffer absorbs part of the ball energy. In addition to this, the lane is provided with a conven¬ tional ball return channel 7.
The measuring area of the camera 1 is marked by dotted lines in the drawing. The length of the measuring area on the lane is preferably about 2 meters. Normally the measuring takes place at two points: when the ball en¬ ters the visual field of the camera, and when it dis¬ appears therefrom. The display device 8 is mounted on a suitable place adjacent to the approach lane 3.
The block diagram and the coupling arrangements of the measuring apparatus are illustrated in Figure 2. The apparatus comprises, in addition to the camera 1 , means 10, 16 and 18 for processing the video signal, ;vhich means include the detector 10, which is compiled of a • video amplifier and a comparator, the particular measu¬ ring member 11 and the microprocessor 12 together with
its interface circuits 13. The interface circuits con¬ nect, among others, 'the keyboard 14 and the display de¬ vice 15 to the other members of the apparatus.
The measuring member 11 itself comprises the processing unit 16 of the synchronizing pulses, the timer 17, the unit for sorting out the visual information, the horizon¬ tal calculators 21 and 22 as well as their control unit 19, and the high-frequency oscillator 20.
The measuring apparatus functions as follows. The appa¬ ratus is synchronized according to the field and line pulses obtained from the video signal. In the proces¬ sing unit 16 of the synchronizing pulses they are proces¬ sed so that their voltage level is suitable for the lo¬ gic family to be used, and thereafter they are compiled to form the timing pulses according to the needs of the measuring system.
The processing unit 16 of the synchronizing pulses inclu¬ des an emitter follower, two successive, suitably sized comparators, the first of which is utilized to detect the line pulses and the second to detect the field pul¬ ses, as well as the successive timer circuits, which circuits render the respective timing pulses JTP and KTP for the measuring member 11 , and for synchronizing the operations of the microprocessor with the video signal.
The detector 10 is compiled of a rapid video amplifier and a comparator. The signal obtained at the start of the video amplifier is sorted out according to its ori¬ gin - whether from the bowling ball or from the lane. The level comparison is carried out by means of the com¬ parator, which compares the starting signal of the ampli¬ fier to a suitable comparison voltage. Thus the video signal from the camera 1 gives the digital signal KOM describing the position of the ball. This signal is
7 further fed into the unit for sorting out the visual in¬ formation 18.
The sorting unit 18 of the visual information is repre¬ sented in Figure 3. It comprises a low pass filter, a plurality of logic operation circuits and timer circuits,
First the comparator signal KOM is processed so that the synchronizing pulses and that part of the video signal which falls outside the lane are eliminated. This mas¬ king of the frame is carried out at the beginning of the line by lengthening the line pulse and at the end of the line by starting AND-operation between the masking pulse formed in the double timer circuit and the signal received from the comparator.
Already at this stage it is desirable, by means of the low pass filter 30, to eliminate the short-time pulses surpassing the video treshold and such interference peaks which apparently are not caused by the ball. Af¬ ter filtering, the pulse triggers the timer circuit 31, provided with a Schmitt-trigger input, for an interval respecting roughly the duration period of the line. The line pulse occurring during this interval is pro¬ cessed to form an interruption pulse, which is inverted and fed into the interruption request unit IRQ of the microprocessor. The interruption takes place at the be¬ ginning of the line pulse, so that the operation of the microprocessor 12 can be synchronized with the line frequency of the camera 1.
In this preferred embodiment the timer 17 contains the vertical calculator 17a and the calculator 17b, which is' utilized for generating the measurement starting pul¬ se, according to the instructions of the microprocessor 12, further into the calculator control unit 19. The timer 17 can also include a time calculator 17c, which
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controls the measurement. The calculators 17b and 17c of the timer can also be built within the microproces¬ sor itself.
The control unit 19 is formed of a plurality of logic circuits, which process the timing pulses and the star¬ ting pulse to form the control pulses of the horizontal calculators 21 and 22.
The measuring process is illustrated by means of Figure 4, which shows the bowling lane 4 and the visual field nk of the camera. The measuring is started when the ball is shown on the line at the first measuring point A. Now the visual information sorting unit 18 gives an interruption request instruction for the microprocessor 12, which at a suitable point of time further gives a starting pulse directly or through the timer 17 to the calculator control unit 19. The control unit 19 starts the operation of the horizontal calculators 21 and 22 on the next video signal line counted from the edge C of the lane. Simultaneously timing is started, for example by means of the calculator 7c, in order to define the speed of the ball. The same measuring operation is re¬ peated at the second measuring point B, where the timing is respectively stopped.
The first horizontal calculator 21 counts the pulses of the high-frequency oscillator from the edge C of the lane as far as the edge A1 of the ball, and the second calculator 22 counts the "pulses along the width A1-A2 of the ball as covered by the line. The readings of the calculators are fed into the memory of the microproces¬ sor through the parallel interface circuit 13. On the basis of this information, the x-coordinate of the loca¬ tion of the ball is defined.
By means of the vertical calculator the line pulses are ϋ
counted between the first measuring point A and the se¬ cond measμring point B. The interval 289-3 of the pul¬ ses covers a certain distance on the lane. When this and the number 286 of the lines between the measuring points is found out, the y-coordinate is defined accor¬ ding to the programme recorded in the memory of the mic¬ roprocessor.
The time calculator 17c is' used for controlling the mea¬ suring operation, and the operation of the calculator programmes is started after the ball has passed the mea¬ suring points.
The definition of the speed is carried out by counting, according to the programme and by means of the timer 17, the time-lapse between the two measurements, and by ta¬ king into account the distance defined by the y-coordi- nates.
The microprocessor 12 carries out the necessary measures for preparing the apparatus into operation, for starting the measurement and for recording the results into the memory, for performing the necessary calculations where, according to the measuring results, the speed and direc¬ tion of the bowling ball and/or its deviation from a straight line, defined on the basis of the initial rea¬ dings, are calculated, and for processing the output in¬ to a form suitable for display. As is apparent from the above description, the measurement takes place without the control of the microprocessor.
By means of the keyboard 14, the apparatus receives an initial reading in the form of a desired rolling path, for example E2-F6 in Figure 4, whereafter the deviations p1 and p2 are defined with respect to this desired rol¬ ling path according to the true rolling path AB after the roll has been completed. On the other hand, the
roll can be performed freely without any initial values, in which case the display directly gives the direction AB and the speed of the roll.
Instead of a normal TV-camera, for example a line-scan camera included in a CCD-circuit (Charged Coupled Device circuit) can be utilized in the measuring apparatus. In that case it is advantageous to' use two arrays of lenses, the first whereof is focused at the measuring point A of Figure 3, and the second at the point B, so that the line having the same width as the lane can be seen in the line scan camera at two points of the alley. The measuring operation can in principle be carried out in similar fashion as above.
The timer 17 of the measuring apparatus can be provided for example with a programmable timer MC 6840 or alterna¬ tively suitable calculator circuits. As the micropro¬ cessor 12 and the interface circuits can be utilized cir-. cuits MC 68Q2 and MC 6820 respectively. It is maintai¬ ned that on the circuit level an expert can realize the operations included in each separate block of Figure 2 in many different ways, wherefore they are not dealt with in much detail.