EP3139348B1 - Method and system for measuring reaction time at the start of a race - Google Patents

Description

Field of the invention

The invention relates to a method for measuring or determining a reaction time of an athlete at the start of a race.

The invention also relates to a system for measuring or determining a reaction time of an athlete at the start of a race for the implementation of the method.

Background of the invention

In a sports competition such as a track and field sprint race, each athlete starts from a starting block. In high level competitions, it is necessary to measure the reaction time of each athlete when starting from the starting block. This is usually done by electronic or optical means while being connected to a base station for the determination of any false start. According to the rules of these athletics competitions, it is defined that a reaction time below a time threshold of 0.1 s should be considered a false start.

Currently, two technologies are mainly planned to measure the reaction times of athletes from a starting block. One of these technologies consists in measuring the force of the athlete resting with at least one of his feet against a stud of the starting block as described in the patent. EP 2 532 400 B1 . Another of these technologies is to determine the backward acceleration of the stud against which one of the athlete's feet is resting and pushing him initially as described. in the patent application WO 99/32889 A2 . According to these two technologies, it is possible to detect the reaction of each athlete even before their movement at the time of departure is visible to the human eye. In the event of a false start, the two aforementioned technologies can provide a graphical representation of the signals from the sensor placed on the starting block as a function of time. This allows one or more judges to consult the graphics to determine a false start. However, these technologies do not make it possible to detect any type of movement of the athlete for a determination of a false start, which constitutes a drawback.

It should also be noted that with an arrangement of sensors arranged only on the starting block, this does not make it possible to determine any movement of the athlete, in particular of an upper part of the body which may allow the determination of a false start. . In addition, it is very difficult to differentiate the greater variations in strength of strong athletes on the starting block versus a weaker athlete, such as a junior to be able to judge a false start.

At the time of the signaling by the starting judge to prepare for the start, an athlete may still move until he is leaning to be considered ready for the start. Any movement occurring before 0.1 s of the start signaled by a starting pistol of the starting judge must be considered as a false start. This means that the movement of the athlete, which results from the loss of contact of the athlete's hand on the starting ground, is considered a false start after the signal of the starting pistol. On the other hand, any movement of the athlete before the preparation signaled by the starting judge with a disconnection in time of the measuring device, will be considered as the preparations before the start and must not be considered as a false start. In this case, the athlete can only receive a disciplinary warning.

It is also known from the patent US 5,467,652 , a starting block for an athletics race. The starting block includes a longitudinal anchoring bar, on which are placed two support blocks of athlete's feet and which are placed on either side of the bar respectively. Each stud includes an angularly adjustable support surface for an athlete's foot. Each bearing surface is coated with a pressure pad made from a conductive elastomer. The pressure pad sensors are connected to a control and display module by electrical cables to provide analog output signals varying according to the measured pressure. A start signal for a race provided by an indicator is transmitted via an electric cable to the module. The starting block is able to measure, record and display the pressure levels detected on each support surface, the time elapsed between the start signal and the departure of the athlete according to the pressure variation measured on the plots, and indicate the false starts. As previously indicated, this does not detect any type of movement of the athlete at the time of the start for a determination of a false start, which is a drawback.

We can also cite the patent application FR 2,089,076 , which describes a device capable of determining a false start for a running race. To do this, a contactor is attached to a rear part of a starting block of a starting block. This contactor controls an electronic circuit so as to signal any false start. Any type of movement of the athlete at the time of the start cannot be detected for a determination of a false start, which is a disadvantage.

The patent application CH 707 401 A2 describes a method and a system for measuring time in a sports competition with at least one personalized transponder module placed on the competitor. The module can be activated at the start of the race, or in intermediate positions of the race course or at the finish. A variation of movement is detected by a movement sensor of said module. Motion measurements can be transmitted from the module to a base station to monitor a run time. An athlete's reaction time at the start of a race is not determined.

The patent application US 2015/0116497 A1 describes a system for determining a running time of an athlete. To do this, the athlete covers a part of his body. A first measuring device, comprising an accelerometer, is placed on a part of the athlete's body. The first measuring device is activated upon receipt of a start signal and can determine a speed at the time of departure, that is to say a reaction time between the moment of the start signal and the actual departure. of the runner. A false start of a race is not determined.

The patent application WO 2015/106077 A1 describes a method and system for calculating athletic performance along multiple measurement axes during athletic activity of a person. One or more sensors measure an activity parameter of a person and provide measurement signals to a processor, which analyzes the activity parameter, which must be according to a predetermined criterion. The sensor (s) are in particular movement sensors, such as an accelerometer or a gyroscope, for determining the change from a static state to an active state. A time interval is determined for the transition from the static state to the active state. A false start of a race is not determined.

Summary of the invention

The object of the invention is therefore to overcome the drawbacks of the above-mentioned state of the art by proposing a method for measuring or determining a reaction time of an athlete at the start of a race.

To this end, the invention relates to a method for measuring or determining a reaction time of an athlete at the start of a race, which comprises the characteristics defined in independent claim 1.

Particular steps of the method for measuring or determining a reaction time of an athlete at the start of a race are defined in dependent claims 2 to 7.

An advantage of the measurement method is that with the transponder module placed on a part of the athlete's body, it is possible to configure the measurement system in such a way as to differentiate any movement of the athlete before preparation. actual start of the race and the actual moment of the start of the race, where the reaction time must be judged. This allows the start judge to make a good decision as to whether the athlete has a false start or not.

Advantageously, each transponder module can be woken up at the time of preparation for the start signaled by the starting judge and coming from a base station or a starting point of the race, such as a transmitter from a starting point. -block, or directly at the instant of the starting pistol shot. As soon as the transponder module is awakened, it can be considered that it is easy to determine the reaction time of each athlete following the start signal of a starting pistol from a starting judge.

To this end, the invention also relates to a system for measuring or determining a reaction time of an athlete at the start of a race for the implementation of the measurement method, and which comprises the characteristics defined in claim independent 8.

Particular embodiments of the system for measuring or determining a reaction time of an athlete at the start of a race are defined in dependent claim 9.

Brief description of the drawings

• la figure 1 représente schématiquement les principaux éléments d'un système de mesure ou détermination d'un temps de réaction d'un athlète au départ d'une course selon l'invention,
• la figure 2 représente de manière schématique un athlète, qui est muni d'un module à transpondeur en position de départ sur un starting-block selon l'invention, et
• les figures 3a à 3c représentent des graphes dans le temps de l'accélération de l'athlète au moment du départ, de la vitesse de rotation du haut de son corps portant le module à transpondeur et l'angle de rotation du corps par rapport à un seuil de confirmation de départ.

The aims, advantages and characteristics of the method and system for measuring or determining a reaction time of an athlete at the start of a race according to the invention will appear better in the following description of at least one embodiment not. limitative illustrated by the drawings in which:

• the figure 1 schematically represents the main elements of a system for measuring or determining a reaction time of an athlete at the start of a race according to the invention,
• the figure 2 schematically represents an athlete, who is provided with a transponder module in the starting position on a starting block according to the invention, and
• the figures 3a to 3c represent graphs over time of the athlete's acceleration at the time of departure, the speed of rotation of the upper body carrying the transponder module and the angle of rotation of the body relative to a confirmation threshold of departure.

Detailed description of the invention

In the following description, all the elements of the system for measuring or determining a reaction time of an athlete at the start of a race for the implementation of the measurement method, which are well known to those skilled in the art in this technical field, will only be related in a simplified manner.

The figure 1 schematically represents the main elements, which make up a system for measuring or determining a reaction time of an athlete at the start of an athletics race. To do this, the system comprises one or more transponder modules or circuits 1 and at least one base station 10 for the communication of data and / or measurements and / or commands between the modules or circuits to transponder 1 and the base station 10. Each transponder module 1 for competition is arranged on a part of the body of an athlete, for example in a numbered bib, and is therefore personalized to the athlete, who wears it. Preferably, the transponder module 1 is disposed on an upper part of the athlete's body, such as the thorax, so as to detect the rotation of the upper body of the athlete for the determination of a reaction time to the athlete. start of the race.

The transponder module 1 can be of the active type with a battery or solar cell integrated in the module or of the passive type while being powered by the reception of a traditional interrogation signal.

The transponder module or circuit 1 comprises a wireless signal receiving unit 3 for receiving by an antenna 2 data signals or commands 3 coming from a base station 10 or from a transmitter arranged in a starting block of the measurement system or along a race track. Preferably, the signals received by the antenna 2 linked to the reception unit 3 are signals allowing the waking up of the transponder module 1, which is in an idle state before the reception of such signals. These wake-up signals are generated, as indicated above, by the base station 10 or by a transmitter of the starting block or along the race route, after the signal of preparation for the start of an athletics race in particular. or directly at the moment of the starting pistol shot. The gun can be an electronic or powder gun with a transducer and can also be part of the measuring system.

The transponder module 1 further comprises a processing unit 4, which can be a state machine, a processor or a microcontroller, for the management of all the data or commands or measurements to be received or transmitted. The processing unit 4 receives the data or commands formatted in the reception unit 3 so as to also wake up all the components, which make up the transponder module 1. The processing unit 4 is still connected to a unit. transmission of signals 5 by an antenna 6 to the base station 10. Base station 10 can be a race timing system and comprises an antenna 11 for transmitting or receiving signals.

The transponder module 1 further comprises at least one movement sensor 7, 8 linked to the processing unit 4 to supply measurement signals continuously or intermittently to the processing unit 4 once the transponder module is wake up. The transponder module 1 can include as a motion sensor an accelerometer 7 and / or a gyrometer or gyroscope 8. Preferably, an accelerometer 7 is provided for measuring the acceleration of an athlete at the start of the race and a gyroscope 8 for determining a speed of rotation and an angle of rotation of the upper part of the athlete's body so as to determine a reaction time at the start of a race. The measurement signals are supplied directly to the processing unit 4.

The accelerometer 7 used can be an accelerometer with one, two or three measurement axes to provide a measurement signal relating to a variation in movement of said module or of a level of vibrations of said module, such as spasms or contractions or trembling. of the athlete before the start of the race. The gyroscope 8 can also be a gyroscope with one, two or three measurement axes and constitute a detection assembly with the accelerometer to provide a measurement signal relating to the speed of rotation of the athlete's upper body and the angle of rotation for determining a reaction time at the start of the race.

The measurement signals from the accelerometer 7 and the gyroscope 8 or other types of sensors are sampled by the processing unit 4. The measurement signals can be transmitted directly to the base station 10 using the control unit. wireless transmission 5. However, the measurement signals can be improved, in particular after filtering and then stored and / or sent subsequently to the base station 10. It can also be provided to process the data of the various sensors and any event of detection, such as a jump. It may still be expected to deal with extracted motion characteristics, such as the step frequency and transmit this information to the base station 10 in addition to the actual data from the accelerometer 7 and the gyroscope 8.

It should also be noted that the signals received by the antenna 2 linked to the reception unit 3 can be low-frequency signals of the order of 125 kHz, while the signals transmitted by the antenna 6 linked to the The transmission unit 5 can be UHF signals at a frequency between 300 MHz and 3,000 MHz. However, it may be conceivable to have a transponder module with a single switchable receive and transmit antenna for receiving or transmitting data signals. In this case, it is preferred to have a reception of at least one wake-up signal and a transmission of data signals at a similar carrier frequency with modulation of the transmitted data FSK, BPSK, QPSK or ON-OFF Keying.

To understand the process of determining a reaction time at the start of a race, the figure 2 represents an athlete, who is provided with a transponder module in the starting position on a starting block according to the invention. The two feet of the athlete 30 are supported against two support pads 21 of a starting block 20 arranged and fixed on the ground of the race track. The athlete 30 is equipped with a transponder module 1, preferably of the active type. The transponder module 1 is provided with at least one movement sensor, and preferably with two movement sensors, such as the accelerometer and the gyroscope.

After the start preparation has been ordered by the start judge or starter, the athlete can move to his final position before the start. Thus, he is supposed to remain ready until the moment of the starting pistol shot fired by the starting judge. During this preparation phase, no other acceleration other than the gravitation of the earth should be seen by the accelerometer. In addition, the gyroscope should also not see a rotation of the body. After firing the starting pistol, the athlete pushes against the support pads 21 for his start of the race. From this moment, the accelerometer measures upward and forward acceleration a and the gyroscope measures rotation or rotational speed ω, as the athlete moves from a squatting position, where their body leans forward approximately 120 ° to an upward (straight) position upon departure. The measurements performed by the two sensors are processed in the processing unit and managed directly in said processing unit or transmitted directly to a base station for processing. The wakeup signal from the transponder module can be generated by a transmitter linked to the starting block 20 or directly from the base station on the command of the starting judge, for example.

To determine a reaction time at the start of a race, the figures 3a, 3b and 3c following represent the absolute acceleration or along the X and Y axes measured by the accelerometer, the speed of rotation and the angle of rotation of the athlete with the transponder module in time after the generation of the starting pistol shot signaling the start of the race. The angle of rotation of the figure 3c is the integration of the signal from the figure 3b and is not useful for the detection of the reaction time, but the signal of the figure 3c is then used to determine if there is truly a false start.

We can thus notice the signals of the sensors during the start of a sprint. A combination of the sensor readings can be used to determine if this is an actual athlete start or only movements preceding the actual start of the race. The start of an increase in athlete's acceleration at the figure 3a is represented by a vertical line, just like the start of a rotation or speed of rotation of the upper body of the athlete at the figure 3b . As mentioned above, the angle of rotation is shown at figure 3c to subsequently determine a real false start. What appears fastest is used as a trigger to determine the reaction time of the athlete, especially after receiving the signals from the transponder modules of each athlete at the start in the base station.

The detection of these events in the signals from the sensors can be carried out in the transponder module, which transmits these events or in the base station, if the transponder directly transmits the measuring signals from the sensors. The base station also receives the start signal of the race generated by the starting pistol shot of the starting judge. The time difference between the start signal and the start of the movement defines the reaction time, which must not be less than the time threshold of 0.1 s to validate a good start of the athlete. In general, the basic detection principle described for this invention is relatively similar, to what is done by sensors arranged in the starting block, but with the difference, that the sensors of the transponder module directly measure the movement of the athlete, whereas with sensors arranged in the starting block the athlete's movement is determined indirectly. This can make the determination of the reaction time at the start of the race less precise with the sensors in the starting block, as it cannot detect any type of movement.

With the method of determining reaction time at the start of a race, account must still be taken of the effect of spasms or contractions, wobbling and starting of the athlete. A big problem with the standard starting block solution is that the contractions of strong athletes cause more variation in force on the starting block than a start of a junior athlete. Thus the contractions sometimes lead to reaction times, which are triggered incorrectly when a false start is detected. While an athlete can get a disciplinary warning for contractions from the starting judge, it is not considered a false start. Only movement, which results from loss of contact of the athlete's hands from the ground should be considered for reaction time.

Using the acceleration of the motion sensor, such as the accelerometer, can lead to the same problem as the measurement made in the starting block. The range of acceleration between athletes can be very large. On the other hand with the additional use of a gyroscope in the transponder module, this allows to have a sure indication of the rotation of the upper part of the athlete's body at the time of departure. This allows to be able to judge in the same way an elite athlete and a junior athlete without taking into account the range of forces or acceleration of each athlete on the starting block.

Although the tilt of the upper body in the squatting position and the tilt of the body following the athlete's first steps or first strides may vary between athletes, it can be concluded that after a body rotation around 30 °, the athlete actually leaves. The start can also be confirmed with his hands, which leave contact with the ground at the start. By integrating the speed of rotation figure 3b measured by the gyroscope, the angle of rotation is obtained in figure 3c of the upper part of the body.

Thus, the measuring system for the implementation of the method for determining the reaction time can detect the start of acceleration or rotation with a very low threshold and then confirm that it is a real start, when the angle of rotation increases above a defined threshold as shown in dotted lines in figure 3c . If the angle remains below the threshold, for example below 30 ° rotation angle, these are twitching or spasms of the athlete before the start, which should be ignored for the determination of the reaction time to the start. departure.

Tremor can be removed from the analysis in a manner very similar to the contractions detected. There are therefore two cases to consider. First, the tremor may have no rotational component. Thus, if significant acceleration is detected, which is not followed directly by significant rotation, then this should not be used as a trigger to determine reaction time. Second, there may be rotational components in the shake. In this case, one can have a significant acceleration and rotation speed detection. However, the angle of rotation will not increase continuously, but will oscillate around 0 °. So, if significant acceleration or rotation is detected, which is not followed by continuously increasing the angle of rotation, this should not be used as a trigger to determine a reaction time and thus a possible false start.

The transponder module can include several other sensors, such as a temperature sensor for example. The transponder module can be placed in other places of the athlete's body for a sports competition other than athletics, for example, where a reaction time must be monitored at the start of the race.

Claims (9)

1. Process for measuring or determining a reaction time of an athlete (30) at the start of a race by means of a personalised transponder module (1) positioned on an upper part of the body of the athlete and a base station (10) of a measurement system, the transponder module (1) comprising at least a signal receiver unit (3), a processing unit (4) for data, measurements or commands, a transmitter unit (5) for data and/or measurement and/or command signals, and at least one first motion sensor (7, 8) to supply measurement signals to the processing unit (4), said first motion sensor comprising a gyroscope (8) with one, two or three measurement axes,
   the process comprising the steps of:

   - activating the personalised transponder module (1) following the receipt of a wake-up signal in the receiver unit (3),

   - measuring the speed of rotation and the angle of rotation of the transponder module (1) on the athlete (30) by the gyroscope (8) following at least the signalling of a starting signal of the race,

   - determining variations in rotation of the transponder module (1) following the starting signal in the processing unit (4),

   - transmitting the measurement signals directly or formatted, as well as data signals on the basis on the variations in rotation of the transponder module (1) by the transmitter unit (5) to the base station (10),

   - determining a reaction time of the athlete (30) at the start of the race on the basis of the variations in rotation of the transponder module (1) in the base station (10) or in the processing unit (4) of the transponder module (1), taking into account the angle of rotation of the transponder module (1) worn on the upper part of the body of an athlete, the angle of rotation must be defined above a defined threshold to confirm a real start of the race of the athlete (30), and

   - determining a possible false start, if the defined reaction time is below a time threshold determined following an integration of the speed of rotation of the athlete (30) with the transponder module (1) with the time after the generation of the starting signal.
2. Measurement process according to claim 1, for which a second motion sensor is an accelerometer (7) with one, two or three measurement axes, characterised in that after having activated the transponder module (1) by the wake-up signal, the accelerometer (7) measures the acceleration of the athlete (30) following the signalling of the start of the race, and in that the transmitter unit (5) transmits the measurement signals supplied by the processing unit (4) directly to the base station (10), or transmits to the base station (10), data signals on the basis of the variations in acceleration as determined in the processing unit (4) following the start of the race.
3. Measurement process according to claim 2, characterised in that after having activated the transponder module (1) by the wake-up signal, the accelerometer (7) and the gyroscope (8) measure the acceleration of the athlete (30), on the one hand, and the rotation speed of the transponder module (1) on the athlete (30), on the other hand, following the signalling of the start of the race, and in that the transmitter unit (5) transmits the measurement signals of the accelerometer (7) and the gyroscope (8) supplied by the processing unit (4) directly to the base station (10), or transmits to the base station (10), data signals on the basis of the variations in acceleration and variations in rotation of the transponder module (1) as determined in the processing unit (4) following the start of the race.
4. Measurement process according to claim 1, characterised in that the wake-up signal is received by the receiver unit (3) of the transponder module (1) to activate it from the base station or an emitter at a race starting point of the athlete (30) after a signalling for preparation of the start of an athletics race or directly at the instant of a starting signal, generated by a starting gun shot of the measurement system.
5. Measurement process according to one of claims 2 to 4, characterised in that the athlete (30) pushes against bearing blocks (21) of a starting block (20) for a start of an athletics race, and in that the motion sensor or sensors (7, 8) measure an acceleration and/or a rotation speed of the transponder module (1) positioned on an upper part of the body of the athlete (30) for determination of a reaction time following the starting signal.
6. Measurement process according to one of claims 1 or 3, characterised in that after having activated the transponder module (1) by the wake-up signal, the gyroscope (8) or the accelerometer (7) and the gyroscope (8) supply measurement signals to the processing unit (4) to determine directly in the processing unit (4) the reaction time following the signalling of the start of the race on the basis of a threshold of the increase in acceleration and/or of the speed of rotation of the transponder module (1) before transmitting the data signals to the base station (10) to determine a possible false start if the reaction time is below the time threshold determined after the generation of the starting signal.
7. Measurement process according to one of claims 1 or 3, characterised in that after having activated the transponder module (1) by the wake-up signal, the gyroscope (8) or the accelerometer (7) and the gyroscope (8) supply measurement signals to the processing unit (4) for the transmission of measurement signals by the transmitter unit (5) to the base station (10) in order to determine in the base station the reaction time following the signalling of the start of the race on the basis of a threshold of the increase in acceleration and/or of the speed of rotation of the transponder module (1), and to determine the possible false start, if the reaction time is below the time threshold determined after the generation of the starting signal.
8. System for measuring or determining a reaction time of one or more athletes (30) at the start of a race for implementing the measurement process, according to one of the preceding claims, the measurement system comprising at least one personalised transponder module (1) positioned on an upper part of the body of an athlete (30) and a base station (10), said transponder module (1) comprising at least a signal receiver unit (3), a processing unit (4) for data, measurements or commands, a transmitter unit (5) for data and/or measurement and/or command signals, and at least one motion sensor (7, 8) to supply measurement signals to the processing unit (4), said first motion sensor comprising a gyroscope (8) with one, two or three measurement axes, characterised in that the transponder module is configured to be woken up by a wake-up signal received by the receiver unit (3) in order to enable the gyroscope (8) to measure the speed of rotation and the angle of rotation of the transponder module (1) on the athlete (30) following a signalling of the start of the race, in that the base station (10) or the processing unit (4) are adapted to determine a reaction time at the start of the race on the basis of measurement signals from the gyroscope (8), taking into account the angle of rotation of the transponder module (1) worn on the upper part of the body of an athlete, the angle of rotation must be defined above a defined threshold to confirm a real start of the race of the athlete (30), and in that the base station (10) or the processing unit (4) are adapted to determine a possible false start, if the defined reaction time is below a time threshold determined following an integration of the speed of rotation of the athlete (30) with the transponder module (1) with the time after the generation of the starting signal.
9. Measurement system according to claim 8, characterised in that a second motion sensor is an accelerometer (7) with one, two or three measurement axes.

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