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WO1997034262A1 - Appareil et procede de chronometrage - Google Patents

Appareil et procede de chronometrage Download PDF

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Publication number
WO1997034262A1
WO1997034262A1 PCT/AU1997/000156 AU9700156W WO9734262A1 WO 1997034262 A1 WO1997034262 A1 WO 1997034262A1 AU 9700156 W AU9700156 W AU 9700156W WO 9734262 A1 WO9734262 A1 WO 9734262A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
loop
timing
timing line
frequencies
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/AU1997/000156
Other languages
English (en)
Inventor
Gerard Leslie Green
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dorian Industries Pty Ltd
Original Assignee
Dorian Industries Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dorian Industries Pty Ltd filed Critical Dorian Industries Pty Ltd
Priority to AU19166/97A priority Critical patent/AU705614B2/en
Publication of WO1997034262A1 publication Critical patent/WO1997034262A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C1/00—Registering, indicating or recording the time of events or elapsed time, e.g. time-recorders for work people
    • G07C1/22—Registering, indicating or recording the time of events or elapsed time, e.g. time-recorders for work people in connection with sports or games
    • G07C1/24—Race time-recorders

Definitions

  • the present invention relates to a timing apparatus for determining the time at which each of a number of moving bodies passes over a timing line.
  • the timing apparatus is of the kind wherein contestants in a race each carry a transmitter which emits a signal received by an antenna located in the vicinity of the finish line to time the contestants.
  • the invention relates to an apparatus for indicating the elapsed time for each of a number of horses on a race track from a starting gate to a finish line.
  • the invention may also be implemented in determining split times around the race track.
  • the invention is not restricted in its application to race meetings and may have application in other types of events such as car racing, athletic track events and other animal racing.
  • the invention also relates to a method of determining the time at which each of a number of moving bodies pass over a timing line.
  • a timing apparatus for determining the time at which each of a plurality of moving bodies passes over a timing line, said apparatus including: a transmitter for mounting to each moving body, each transmitter adapted for transmitting a signal at a unique characterizing frequency; a signal receiving means associated with the timing line, the signal receiving means for receiving a composite signal comprised of signal components having frequencies corresponding to the unique characterizing frequencies of the signals transmitted from the transmitters within a predetermined range of the timing line; and a signal processing means including a signal resolving means to resolve the composite signal into each of the signal components to determine the times at which each of the moving bodies associated with each signal component crosses the timing line.
  • each signal component being at one of the unique characterizing frequencies may be associated with the transmitter transmitting at that unique characterizing frequency and with the moving body carrying that transmitter.
  • the resolving means may comprise a means for conducting a fourier analysis of the composite signal to resolve it into each of the signal components. Specifically, this fourier analysis can be implemented by software stored in ROM provided on a digital signal processing card.
  • the resolving means may include a digital sampling means to take samples of the composite signal and means for conducting a discrete fourier analysis of the digitised samples.
  • the means for conducting the discrete fourier analysis may be a means for conducting a fast fourier transform (FFT).
  • FFT fast fourier transform
  • the resolving means may also include a filter to attenuate frequencies outside the range of the unique characterizing frequencies.
  • the resolving means may be adapted to determine the relative amplitude of each of the signal components and the processing means may include an analyzing means adapted to analyze the relative amplitude of each of the components to determine the time at which the moving body associated with each component crosses the timing line.
  • the signal receiving means may comprise a loop in substantial alignment with the timing line and the analyzing means is adapted to compare the relative amplitude of each signal component relative to a threshold to determine the time at which the moving body associated with each signal component crosses the timing line.
  • the signal receiving means may be in the form of an inductive loop in which the composite signal is generated as a plurality of moving bodies transmitting signals at respective characterizing frequencies, pass over the loop.
  • the loop may encompass or straddle the timing line, with side portions parallel to the line, the spacing of the side portions being such that the relative amplitude of each signal component generated in the loop drops below the threshold due to a canceling effect in the centre of the loop.
  • an average may be taken of the times at which the relative amplitude crosses the threshold value to determine the time of crossing of the moving body associated with the signal component.
  • the unique characterizing frequencies can be spaced apart at regular frequency intervals.
  • the spacing of the characterizing frequencies should be selected such that they can be resolved by the resolving means.
  • the resolving means should be designed with the capability of resolving all the preselected unique characterizing frequencies.
  • the signal receiving means may be embedded in the ground and thus low frequencies are desirable as the unique characterizing frequencies to enable penetration through the ground.
  • the signal receiving means may be embedded in the ground or beneath a racing track. This is particularly desirable in horse racing applications since the tracks are pierced by spikes to aerate the track. Thus the signal receiving means is suitably embedded below the level of penetration.
  • a method of determining the time at which each of a plurality of moving bodies passes over a timing line including the steps of: transmitting a signal from a transmitter mounted on each moving body, each signal having a characterizing frequency unique to that transmitter; receiving by a signal receiving means, a composite signal comprised of signal components having frequencies corresponding to the characterizing frequencies of the signals transmitted from the transmitters within a predetermined range of the timing line; processing the composite signal including the step of resolving the composite signal into each of the signal components by a signal resolving means to determine the times at which each of the moving bodies associated with each signal component crosses the timing line.
  • the step of resolving may comprise conducting a fourier analysis of the composite signal.
  • the step of resolving may further comprise conducting digital sampling of the composite signal and conducting a discrete fourier analysis of the digital samples.
  • the step of conducting a discrete fourier analysis may comprise conducting a fast fourier transform (FFT) of the digital samples.
  • FFT fast fourier transform
  • the step of digital sampling may comprise undersampling and the step of resolving may include an initial step of filtering the composite signal.
  • the step of resolving the composite signal may include the step of determining the relative amplitude of each signal component and the step of processing may further include a step of analyzing the relative amplitude of each signal component to determine the time at which the moving body associated with each signal component crosses the timing line.
  • the signal receiving means may comprise a loop in substantial alignment with the timing line
  • the step of analyzing may include the step of comparing the relative amplitude of each signal component with a threshold for determining the time at which the moving body associated with each signal component crosses the timing line.
  • Fig. 1 is a schematic view of a timing apparatus in accordance with a preferred embodiment of the present invention
  • Fig. 2 is a schematic view of a portion of the timing apparatus shown in Fig. l;
  • Fig. 3 is a graph of signal strength vs. t e for a transmitter passing over a signal receiving loop shown in Fig. 1;
  • Fig. 4 is a circuit diagram of a transmitter schematically shown in Fig. 1;
  • Fig. 5 is a circuit diagram of a receiver card schematically illustrated in Fig. 2;
  • Figs. 6A and 6B are circuit diagrams of a DSP board schematically illustrated in Fig. 2.
  • Fig. 7 is a schematic diagram showing analogue to digital sampling of a composite signal.
  • Figure 1 illustrates how the timing apparatus 10 of the present invention can be implemented at a race track 12.
  • the race track 12 includes a turf track 14 on which a number of horses 16 run towards the winning post 18.
  • Each of the horses 16 carries in its saddlecloth, a transmitter 17 which transmits a signal at a unique characterizing frequency.
  • the loop 20 is buried below the surface of the track by up to a meter. A depth of at least 500 mm is required because race tracks are generally penetrated by spikes to improve aeration. It is also desirable to bury the loop 20 since shallow loops in loose soil could trip an animal.
  • the loop will be approximately 30 meters in length, depending upon the width of the track 14.
  • the width of the loop 20 is approximately 1 meter, the loop straddling a timing line 22 extending across the track 14 from the winning post 18 at right angles to the longitudinal direction of the track 14.
  • each transmitter 17 transmits a signal at a unique characterizing frequency.
  • the transmitters transmit signals at the following frequencies:
  • TX1 368.1kHz
  • TX2 369.5kHz
  • Relatively low frequencies are selected to enable penetration through the track 14 to the signal receiving loop 20. It will be appreciated by those skilled in the art that lower frequencies have greater penetration.
  • Each transmitter 17 includes an antenna 24 which is not shown in detail in the figures.
  • the antenna is wound on a ferrite rod having a rectangular section of 17 mm x 3.5 mm and a length of 50 mm.
  • the antenna coil comprises between 40 and 80 turns of 26 gauge wire. It is important for the operation of the apparatus 10 that the axis of the antenna coil, in this case the longitudinal direction of the ferrite rod, extends in the direction of travel of the horses 16, otherwise, little signal will be detected in the loop 20.
  • the antenna coil carries AC current at a voltage of between 20 and 60 volts.
  • the signal receiving loop 20 is a loop formed from a signal piece of wire, the ends of which are connected to a receiver module 26.
  • a signal of approximately 20 to 60 volts in the antenna coil of a transmitter 17 produces by inductance a signal component of approximately 10 microvolts in the signal receiving loop 20 when the transmitter 17 is within a predetermined range of the loop 20. This range is approximately 4 to 6 meters. When a number of transmitters 17 are within range of the loop 20, this produces within the loop, a composite signal which is made up of signal components at frequencies corresponding to the characterizing frequencies of the transmitters 17, plus, of course ambient noise.
  • the ends of the loop 20 extend to a receiver box 26 as shown in Fig. 2.
  • the ends of the loop are twisted together to minimize interference especially differential mode noise.
  • Fig. 2 in a schematic way, shows the elements of the receiver box 26.
  • the receiver box 26 includes a receiver card 32 and a digital signal processing (DSP) card 34.
  • Figure 5 is a diagram showing the elements of the receiver card 32
  • Figures 6A and 6B are diagrams of the elements of the DSP card 34.
  • the diagrams contain information such that a person skilled in the art could readily understand the construction and operation of the receiver card 32 and the DSP card 34.
  • the receiver card 32 contains a number of elements including a filter 40, amplifier 42 and a sampling analog to digital (A/D) convertor 44.
  • A/D sampling analog to digital
  • the composite signal received in the inductive loop 20 is passed through an active filter 40 which has a passband to accommodate all possible characterizing frequencies of the transmitters 17. At present the pass band is 366.7kHz to 412.5kHz. This accommodates 31 transmitters at a frequency spacing of 1.432kHz.
  • the filter 40 has a gain of approximately 80.
  • the amplifier 42 comprises two further amplifications stages with a combined gain of 1000 to increase the signal to such an extent that the signal produced by all 31 transmitters will use the entire range of the A/D convertor 44. Utilizing the whole range of the A/D convertor 44 allows for the best amplitude resolution of the composite signal.
  • a sampling A/D convertor 44 is employed.
  • the sampling A/D convertor 44 is controlled by the DSP card 34 which includes a DSP chip 45, RAM 46, ROM 48 and an RS485 convertor 49.
  • the part number of the DSP chip 45 available from Texas Instruments is TMS320C31.
  • the DSP 45 reads the results of the A/D conversions and stores them in RAM 46.
  • the sampling A/D convertor 44 could be located on the receiver card 32. However, this would necessitate the transmission of an analog signal between the receiver card 32 and the DSP card 34. Due to noise problems in transmitting an analog signal, it is preferred that the sampling A/D convertor 44 is located on the receiver card 32. However, the division between the receiver card 32 and the DSP card 34 is arbitrary.
  • the A/D convertor 44 samples at a rate sufficient to resolve each of the signal components. Undersampling is employed in the timing apparatus 10 since its simplifies the receiver card circuit 32. Undersampling is appropriate since it is not necessary to reconstruct the waveform but merely to resolve all incoming frequencies within the passband of the filter 40.
  • the A/D convertor 44 samples at a rate of 91.666kHz. 256 sample points are read for use in calculation. At a sampling rate (f s ) of 91.666kHz, this takes 2.793 ms.
  • the composite signal is produced by an unknown number of transmitters 17 transmitting at various ranges from the receiving loop 20.
  • the A/D sampling is schematically illustrated in Figure 7.
  • Sample data points are stored in an array of floating point numbers p in RAM 46 on the DSP card 34.
  • the array can be represented as follows:
  • the DSP performs an FFT program stored in ROM 48.
  • the code for the FFT program was available from the users guide accompanying the TMS 320C31 chip.
  • the FFT program is a decimated in frequency radix 2, 256 point FFT calculation.
  • Boston Technologies sells a program in the form of code on a disk to perform the calculation.
  • a radix 2 calculation is found to be sufficient for the present timing apparatus 10.
  • a radix 4 calculation which is faster can also be used.
  • the FFT program calculates the relative amplitude of each of the signal components together with the amplitude of signals detected at intervening frequencies.
  • the result is stored in an array of floating point numbers r in the RAM as follows:
  • the relative amplitudes rl28 - r255 actually occur at complex frequencies, producing negative amplitudes, and can have the effect of cancelling out the amplitudes recorded for rO - rl27 often leading to erroneous results. Therefore, to compensate for this, the FFT calculates the absolute value of all numbers rO - r255 and then adds the values for rl28 - r255 to their corresponding values rO - rl27, e.g. I rO I + I rl28
  • the FFT calculates relative amplitudes since it is a phenomenon of FFT that amplitudes appear greater than they are in reality. However, relative amplitudes are sufficient for the timing apparatus 10.
  • the spacing between frequencies which the FFT can resolve can be calculated as follows:
  • the spacing between the frequencies which can be resolved by the FFT is one quarter the frequency spacing between the signals of each of the transmitters. If one of the transmitters does not transmit at exactly its characterizing frequency as prescribed above then any signal generated will "spill over" into an adjacent frequency resolved by the FFT. This provides for greater tolerance in transmitter frequency. Furthermore, this allows future expansion of the apparatus 10 by inserting extra transmitters which transmit at freque n cies between those prescribed above.
  • the present embodiment employs filtering to attenuate all signals outside the range of 366.7kHz to 412.5kHz.
  • the sampling process takes 2.79ms and the FFT calculation about 3.5ms depending upon non-deterministic factors. The process is repeated every 3.5ms. Thus at intervals of 3.5ms, the relative amplitude of each signal component will be known.
  • the process provides accuracies of greater than 1/lOOth of a second, a reliable accuracy of 1/100th of a second is achieved.
  • a graph of relative amplitude vs. time will take the form shown in Fig. 3.
  • the characteristic gull wing shape is produced since as the transmitter approaches the first side of the loop 20, 28, the received signal component increases. Towards the center of the loop 20, 28, the signal component decreases because a signal component received on opposite sides of the loop will in effect cancel with itself.
  • a threshold voltage known as a "squelch" level is automatically chosen to offset any background noise as shown in Figure 3.
  • the points (a), (b), (c) and (d) represent the time at which the relative amplitude strength made a transition through the squelch level.
  • the point (e) can be calculated from the values of (a), (b), (c) and (d). Alternatively, the value of (e) may be determined by averaging the values of (b) and (c).
  • Noise in the local area is sampled to find the average background noise level for each characterizing frequency of the transmitters 17. The value for this level is then multiplied by a safety factor producing a new value which is used to set the squelch level for each transmitter frequency.
  • a safety factor producing a new value which is used to set the squelch level for each transmitter frequency.
  • the timing apparatus 10 also includes a number of other signal receiving loops 28 at spaced locations along the track 14 for determining split times.
  • the signal receiving loops 28 are the same as the loop 20 and the loops 28 are connected to respective receiver boxes 30 which are the same as the receiver box 26.
  • the time is marked by a hardware counter (not shown) on the DSP card 34.
  • the counter is incremented by a clock card (not shown) which generates a 16 MHz signal which then passes to a divider chip (not shown) on the DSP card 34 which divides the signal by 1024.
  • a pulse at 15.625kHz increments the counter.
  • a synch pulse is received from the network node 50 via RS485 network.
  • Each DSP ensures that its counter remains in synch with the synch pulse using a software implemented phase-locked-loop.
  • the counters in each receiver box 26, 30 are kept in synchronization with each other. This is important for accurate recording of split times.
  • the transmitter number, crossing time and some status information are stored in a database in RAM 46 on the DSP card 34.
  • the data is accumulated here so that if, for some reason, the receiver box 26, 30 is isolated from the remainder of the apparatus 10, data can be saved for later retrieval.
  • the network node 50 is generally situated in a timing room adjacent the race track 14. All data from the receiver boxes 26, 30 passes to the network node 50 via the RS485 network. As discussed above, the network also carries the synch pulse to each of the receiver boxes. Data arriving at the network node 50 is converted from RS485 to RS232 and passes to a PC 55 running a program known as "CTC".
  • the CTC program collects and collates data from each of the DSP cards.
  • the CTC program also records the time at which each DSP chip 45 is turned on.
  • the CTC program can record the elapsed time from when the DSP chip is turned on until one of the horses 16 crosses the timing line 22 at the winning post 18 or the timing line associated with the other loops 28.
  • the CTC keeps a database of the time at which each horse 16 passes each of the loops 20, 30.
  • the network node 50 is also connected to the starter button 60 and thus the CTC program receives information as to the start time of each race. Since a database is kept of all loop crossings and the time of start for each race, split times and race times can be calculated by the CTC program.
  • the CTC program can combine data from a number of time lines and process it to produce meaningful results. It is also able to filter out spurious signals in the data stream and to remove duplicate records. It also knows the expected crossing order for transmitters travelling around the track 14 and is able to detect when a particular transmitter 17 goes missing.
  • a light beam is also attached to each loop 20, 28, with the first horse interrupting the light beam and so generating a signal to indicate the finish of the race or the passing of each of the loops 28.
  • the failsafe system is also connected to the starter's button GO.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

L'invention concerne un appareil de chronométrage (10) et un procédé pour déterminer l'instant où chaque corps (16), d'une pluralité de corps en mouvement, traverse une ligne (18). L'appareil comprend un émetteur (17), destiné à être monté sur chaque corps en déplacement. Chaque émetteur (17) est conçu pour émettre un signal à une fréquence caractéristique spéciale. Un moyen récepteur de signaux (20, 28) est associé à la ligne de chronométrage et reçoit un signal composite constitué de composants de signaux, ayant des fréquences correspondant aux fréquences caractéristiques des signaux émis par les émetteurs (17) à une distance prédéterminée de la ligne de chronométrage (18). Un moyen de traitement des signaux (45) comprend un moyen pour décomposer le signal (44) permettant de décomposer le signal composite en composants individuels pour déterminer l'instant où chacun des corps en mouvement (16), associé à chaque composant du signal, traverse la ligne de chronométrage (18).
PCT/AU1997/000156 1996-03-12 1997-03-12 Appareil et procede de chronometrage Ceased WO1997034262A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU19166/97A AU705614B2 (en) 1996-03-12 1997-03-12 Timing apparatus and method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPN8613A AUPN861396A0 (en) 1996-03-12 1996-03-12 Timing apparatus and method
AUPN8613 1996-03-12

Publications (1)

Publication Number Publication Date
WO1997034262A1 true WO1997034262A1 (fr) 1997-09-18

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1997/000156 Ceased WO1997034262A1 (fr) 1996-03-12 1997-03-12 Appareil et procede de chronometrage

Country Status (2)

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AU (1) AUPN861396A0 (fr)
WO (1) WO1997034262A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL2005772C2 (en) * 2010-11-29 2012-05-30 Amb It Holding Bv Method and system for detecting an event on a sports track.

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946312A (en) * 1974-06-25 1976-03-23 Oswald Robert A Timing apparatus and system
US4142680A (en) * 1977-03-21 1979-03-06 Oswald Robert A High resolution timing recording system
US4274076A (en) * 1979-04-07 1981-06-16 Winfried Hermanns Device for determining the moment when competitors in a race are passing the finish line
US4315242A (en) * 1979-04-07 1982-02-09 Winfried Hermanns Device for determining the moment when competitors in a race are passing the finishing line
WO1992010811A1 (fr) * 1990-12-14 1992-06-25 Digital Equipment International Ltd. Appareil servant a mesurer les parametres de fonctionnement de vehicules roulant sur une piste de course, et a les chronometrer
WO1993004446A1 (fr) * 1991-08-23 1993-03-04 Laird Douglas A Appareil de surveillance de course
FR2716990A1 (fr) * 1994-03-01 1995-09-08 Actipole Dispositif d'identification et de pointage de mobiles.

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946312A (en) * 1974-06-25 1976-03-23 Oswald Robert A Timing apparatus and system
US4142680A (en) * 1977-03-21 1979-03-06 Oswald Robert A High resolution timing recording system
US4274076A (en) * 1979-04-07 1981-06-16 Winfried Hermanns Device for determining the moment when competitors in a race are passing the finish line
US4315242A (en) * 1979-04-07 1982-02-09 Winfried Hermanns Device for determining the moment when competitors in a race are passing the finishing line
WO1992010811A1 (fr) * 1990-12-14 1992-06-25 Digital Equipment International Ltd. Appareil servant a mesurer les parametres de fonctionnement de vehicules roulant sur une piste de course, et a les chronometrer
WO1993004446A1 (fr) * 1991-08-23 1993-03-04 Laird Douglas A Appareil de surveillance de course
FR2716990A1 (fr) * 1994-03-01 1995-09-08 Actipole Dispositif d'identification et de pointage de mobiles.

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL2005772C2 (en) * 2010-11-29 2012-05-30 Amb It Holding Bv Method and system for detecting an event on a sports track.
WO2012072382A1 (fr) * 2010-11-29 2012-06-07 Amb I.T. Holding B.V. Procédé et système permettant de détecter un événement sur une piste de sport
CN103380444A (zh) * 2010-11-29 2013-10-30 Ambi.T.控股有限公司 用于检测跑道上发生事件的方法及装置
US10026235B2 (en) 2010-11-29 2018-07-17 Amb I.T. Holding B.V. Method and system for detecting an event on a sports track
CN103380444B (zh) * 2010-11-29 2018-08-10 Ambi.T.控股有限公司 用于检测跑道上发生事件的方法及装置

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