FR3135209A1 - Door Touch Detection System for Whitewater Competition - Google Patents

Abstract

The invention relates to a door touch detection system (1) for white water competition, comprising at least one passage door (5) of a water vehicle (7), in particular a canoe or a kayak, the door of passage (5) having two posts (9, 9') suspended from a support structure (11) by a proximal end (13, 13'). Each post (9, 9') has in its distal end portion (15, 15') which is opposite the proximal end (13, 13'), an inclinometer (17, 17') configured to measure the inclination of the pole (9, 9') suspended relative to the vertical and in that the system further comprises a processing unit (19) receiving a measurement signal from each inclinometer (17, 17') and configured to trigger a door touch signal depending on the measured inclination. Figure for abstract: Fig. 1

Description

Door Touch Detection System for Whitewater Competition Technical field of the invention

The present invention relates to a door touch detection system for white water competition, in particular for canoe or kayak slalom

Technical background

In the field of sporting competitions, particularly at high level, in recent years we have witnessed a proliferation of technology-assisted judging in a wide variety of sports.

While video response has played a role in many sports for some time, it is not suitable for all sporting activities.

Particularly for white water slalom competitions such as canoeing, a video system alone is not suitable due to the difficulty of installation and delivering a result in real time to be able to detect a door touch from various angles and for a route, with more than twenty doors.

The sport of canoeing began in the late 1800s in North America, with races between Indians and the region's early inhabitants.

In the canoe-kayak slalom discipline, where competitors must pass through a number of slalom gates on a whitewater course, the first world championships were held in 1949, and these disciplines made their appearance in the Olympic Games from 1972.

After a hiatus until 2002, canoe slalom (kneeling, using a single paddle) and kayaking (sitting, using a double paddle) have since become an integral part of all games Olympics.

A competition course generally has 18 to 25 gates made of suspended vertical posts between which competitors must pass. At least 6 gates must be negotiated upstream (red/white posts), the others downstream (green/white) and the gates must be negotiated in strict order. In general, the courses measure between 200m and 400m from start to finish, with a passage time of around 100s.

Time penalties are incurred as follows:

- 2s if one or both posts of a door are "touched", and

- 50s if a door is missed.

A difficulty in competition arises from the fact that no clarification is provided on the exact meaning of the term “touch”. While some contact seems obvious and results in pole movement, other, more subtle contacts may result in pole rotation only, or no movement perceptible to the naked eye.

Currently, during major competitions (Olympics, World Championships, World Cups), penalties are judged as follows.

An individual human judge is placed at each gate. Each judge has the possibility of a video review following, for example, a protest from a competitor or a competitor's team.

However, it is necessary to be able to distinguish the natural movement of the door posts due to splashing water (remember that this is a white water course) and the wind.

Additionally, there is an impossibility of having a 360° perspective on each post, either by the judge or by the video system (usually 10 video cameras are used to cover the entire course).

The consequences of a touch, or a misjudged touch, are significant, because in 2012 the gold and bronze medals at the Olympic Games in London were separated by less than a single touching penalty (2 seconds).

In order to provide an answer, the document https://www.researchgate.net/publication/283655752_A_gate_hit_detection_system_for_canoe_slalom) published in 2015 proposed a system whose detection is based on a strike of the rod (“A gate hit detection”). To do this, an accelerometer is placed on the bottom of the rod. During an impact on the rod, the accelerometer transmits temporal information to a computer which calculates the Fourier transform of the signal in order to obtain the spectral response of the signal comprising a set of frequency lines. In summary, an impact results in a touchdown. Depending on the type of impact, the frequencies from the sensors installed (ITG3205/ADXL345 gyroscope/accelerometer) provide a variable temporal signal. A Fourier transform is applied to this same signal. The use of frequency analysis of the signal is supposed to provide, a priori, the type of impact.

The difficulty of this technique lies in the acquisition time and processing of data in real time. During a race, information must be provided in a time period of less than a “second”, or at best a second. Spectral analysis on a low frequency signal (for example 1 Hz) will require at least 2 seconds of acquisition in order to respect the Shannon criterion. This can be the case if a runner brushes the rod with his clothing without giving a real impact unlike a paddle impact.

To have a signature and good exploitation of the signal, around ten samples are necessarily necessary, it is therefore necessary to have an acquisition time of 20 seconds minimum. Under these conditions, this system becomes unusable, in particular for high-level championships which require results in the “second”.

One of the aims of the present invention is therefore to propose a door touch detection system which can deliver with excellent reliability a result in real time during a competition.

For this purpose, the subject of the invention is a door touch detection system for white water competition, comprising at least one door for the passage of a water vehicle, in particular a canoe or a kayak, the door having two suspended posts to a support structure via a proximal end, characterized in that each post has in its distal end portion which is opposite the proximal end, an inclinometer configured to measure the inclination of the suspended post relative to the vertical and in that the system further comprises a processing unit receiving a measurement signal from each inclinometer and configured to trigger a door touch signal as a function of the measured inclination.

Such a detection system is distinguished by its precision of touch detection and its speed of measurement which allows real-time operation, these two aspects being essential for high-level competitions, in particular international/Olympic competitions with more a live television broadcast.

The system is based on the hypothesis that each touch will result in a measurable variation in the inclination of one of the suspended posts and that this inclination relative to the vertical is measured almost instantly in a time of less than 1/10th of a second and this with very high reliability.

The system may further include one or more of the following aspects taken individually or in combination.

According to one aspect, the processing unit determines an inclination differential between the two posts and is configured to trigger a door touch signal when the inclination difference between the two posts is greater than a predefined threshold. The inclination differential can be calculated as the difference between the inclinations of the two posts relative to the vertical.

The predefined threshold, in particular for an inclination differential, is for example less than 7.5° and in particular equal to 5°.

The passage door can be equipped with at least one camera configured to film the passage of a water vehicle, the processing unit is configured to receive camera signals and to determine in particular the direction of passage of the door.

One of the posts of a passage door comprises for example in its distal end portion an optical transmitter and the other post an optical receiver in particular for measuring the passage time of the door in relation to a time of reference.

The emission beam of the optical transmitter has in particular the shape of a fan with an emission angle greater than 30°, in particular equal to 60°.

The reception angle of the optical receiver in a direction perpendicular to the post is in particular greater than 30°, in particular equal to 60°.

The passage door includes, for example, an RFID reader configured to detect during passage an RFID chip carried by the watercraft or the sportsman operating the latter.

The processing unit is notably configured to receive a passage signal to synchronize the door touch measurement with the passage of a water vehicle.

The invention further relates to a sports course for white water competitions, comprising several passage doors for a water vehicle, in particular a canoe or a kayak, characterized in that each passage door comprises a detection system as defined below. -above.

Other advantages and characteristics of the invention will appear on reading the description of the figures which follow, among which:

schematically shows a passage door from the front,

And

show respectively from the front and from above a passage door in the rest state,

And

show respectively from the front and from above a passage door after a touchdown, and

is a cross-sectional view at the distal ends of the posts to illustrate the operation of a light barrier.

In all figures, the same elements bear the same reference numbers.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features only apply to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

We define by upper, lower, lateral, front and rear, upstream and downstream the orientations relating to a passage gate installed on a sports course.

All of the figures show trihedra XYZ or X'Y'Z' in order to define the orientation of the different elements from each other. A first direction, denoted Y or Y’, corresponds to a transverse direction of a passage door. A second direction, denoted X or X', is a so-called door passage direction. It is perpendicular to the directions Y or Y’ and corresponds to the general direction for passing the passage gate with the water vehicle.

Finally, a third direction, denoted Z or Z’, is vertical. The directions, X, Y, Z as well as X’, Y’ and Z’ are orthogonal in pairs. The only difference between the two trihedra XYZ or X'Y'Z' is their origin O or O', the origin O corresponding to the suspension point of one of the two posts of the passage door and the origin O' corresponds at the suspension point of the other post of the passage door.

There shows a door touch detection system 1 for white water competition which is installed above a body of water 3, for example a natural or artificial river.

This system 1 comprises at least one passage door 5 of a water vehicle 7, in particular a canoe or a kayak, represented with an on-board sportsman.

The passage door 5 has two posts 9 and 9' suspended respectively at the suspension points O and O' to a support structure 11 by a proximal end respectively referenced 13 and 13'.

Each post 9, 9' has a distal end respectively referenced 15, 15' which is opposite the proximal end 13, 13' and which is placed approximately ten cm from the body of water 3 in height.

As seen on the , each post 9, 9' has in its distal end portion 15, 15' an inclinometer 17, 17'. Such an inclinometer 17, 17' is in particular a three-axis sensor based on capacitive 3-D MEMS technology with a microprocessor and providing signals corresponding to a variation in the angle / inclination of the posts 9, 9' by relative to the vertical. Such inclinometers 17, 17' are commonly sold commercially and have, for example, a precision of +/- 0.1°.

The inclinometers 17, 17' are integrated and sealed inside the posts 9, 9' which have a tubular shape, at the distal end 15, 15' and are configured to measure the inclination of the posts 9, 9' suspended relative to the vertical (direction Z, Z').

The system further comprises a processing unit 19 which can be housed in a housing fixed to the support structure 11, that is to say the crossbar of the passage door 5.

The processing unit 19 is connected for example by a wire connection which evolves inside the posts 9, 9' to the inclinometers 17, 17' to supply them with current and to receive measurement signals from each inclinometer 17, 17 '. Of course, we can also provide that each inclinometer has its own battery and power supply. The measurement signals can also alternatively be transmitted via a radio link, in particular by Bluetooth (registered trademark).

For this purpose, the processing unit 19 comprises different interfaces and also calculation and processing means, in particular programmable. The processing unit 19 is more particularly configured to trigger a door touch signal as a function of the measured inclination.

According to a first embodiment, a touch signal can be emitted when the inclination of one of the two posts 9, 9' is greater than a predefined threshold.

Good precision can be obtained by choosing the predefined threshold less than 7.5° and in particular equal to 5°.

The processing unit 19 also comprises, for example, telecommunications means for communicating with a central computer for managing a race (race PC) which can be programmed to centralize the data coming from all the passage doors and to count all the touches of a sports course for white water competitions, comprising several gates for a water vehicle to pass through.

To take into account in particular external phenomena, such as for example the wind which tends to impose on each post 9, 9' a non-zero, but similar inclination relative to the vertical, the processing unit 19 is configured to determine a inclination differential between the two posts 9, 9'.

In this case, the processing unit 19 is programmed to trigger, for example, a door touch signal when the difference in inclination between the two posts 9, 9' is greater than a predefined threshold. The inclination differential can be calculated as the difference between the inclinations of the two posts 9, 9' relative to the vertical.

It turned out that good precision can be obtained by choosing the predefined threshold less than 7.5° and in particular equal to 5°.

Figures 2A and 2B show respectively from the front and from above a passage door in the rest state. In this case, the two posts 9, 9' hang vertically in the direction Z / Z' and are parallel. No door touch signal is generated by the processing unit 19 for this situation.

If we assume a little wind, the 9, 9' posts can be slightly tilted, but in the same direction. No door touch signal is generated by the processing unit 19 for this situation either if the triggering of a touch signal is subject to the fact that the difference in inclination between the two posts 9, 9' is greater than a predefined threshold.

Figures 3A and 3B show respectively from the front and from above a passage door when there is contact by the water vehicle 7. In this case for example, the post 9' hangs vertically in the direction Z' while the post 9 is inclined for example by 15° relative to the vertical due to touch by the water vehicle 7. The two posts 9, 9' are then no longer parallel and a door touch signal is generated by the processing unit 19 for this situation.

Furthermore, as can be seen in the , the passage door 5 can be equipped with at least one camera 21 configured to film the passage of a nautical vehicle 7.

The camera 21 is also connected to the processing unit 19. The processing unit is further configured to receive signals from the camera 21 and to determine the direction of passage of a water vehicle 7 between the posts 9, 9' of a passage door 5. Thus, it can be verified that the passage door 5 is crossed in the right direction.

Furthermore, the detection system 1 can further comprise a photoelectric barrier where one of the posts 9 of a passage door 5 comprises in its distal end portion 15 an optical transmitter 23 emitting a light beam 24 and the another post 9' an optical receiver 25 of the light beam 24 in particular for measuring the passage time of the door 5 in relation to a reference time.

As shown schematically on the which shows a cross-sectional view at the distal ends 17, 17' of the posts 9, 9', the emission beam 24 of the optical transmitter 23 has the shape of a fan with an emission angle α by example greater than 30°, in particular equal to 60°.

The reception angle β of the optical receiver 25 in a direction perpendicular to the post 9' is for example greater than 30°, in particular equal to 60° (see diagram ). Such a configuration makes it possible to detect the passage with great reliability.

The fan-shaped emission beam 24 and the reception field in the form of a sector ensure crossing detection even if the 9.9' posts are no longer exactly aligned, for example due to the wind.

The passage door 5 can also include an RFID reader 27 connected to the processing unit 19 and configured to detect during a passage an RFID chip carried by the nautical vehicle 7 or the athlete operating the latter. The RFID reader 27 can be installed on or in the housing containing the processing unit 19 and be arranged in a central position on the support structure 11.

Radio identification, most often referred to by the acronym RFID (from the English "radio frequency identification"), is a method for memorizing and retrieving data remotely using markers called "radio tags" ("RFID tag” or “RFID transponder” in English).

The radio tags include an antenna associated with an electronic chip which allows them to receive and respond to radio requests transmitted by the transceiver.

These electronic chips contain an identifier and possibly additional data.

This makes it possible to clearly identify the athlete passing through gate 5. If necessary, for a sports course of a certain length, this will allow several athletes to be on the course at the same time while allowing time and touch measurements. accurate. This can be particularly interesting for training or qualifying races.

The processing unit 19 can also be configured to receive a passage signal, either via the RFID reader 27 or via the photoelectric barrier 23, 25 to synchronize the door touch measurement with the passage of a water vehicle 7.

Preferably, RFID technology is used with an RFID detection range adjusted so that a watercraft 7 can be detected approximately 1m or 50cm upstream of the passage door 5, this allows the detection of touch via the processing unit 19 and to then “disarm” the detection just after the passage when the water vehicle 7 is downstream of the passage door 5.

The invention also relates to a sports course for white water competitions, comprising several passage doors, for example between 10 and 20, of a water vehicle 7, in particular a canoe or a kayak, equipped with a detection system 1 such as described above.

We therefore understand that the detection system allows rapid, real-time and reliable detection of the touch of a passage door during a sports competition. Thus, we can reduce the number of referees necessary, or even dispense with them, along the sporting route without sacrificing the precision and accuracy of race results for high-level competitions.

Claims (10)

Door touch detection system (1) for white water competition, comprising at least one passage door (5) of a water vehicle (7), in particular a canoe or a kayak, the passage door (5) having two posts (9, 9') suspended from a support structure (11) by a proximal end (13, 13'), characterized in that each post (9, 9') has in its distal end portion (15 , 15') which is opposite the proximal end (13, 13'), an inclinometer (17, 17') configured to measure the inclination of the pole (9, 9') suspended relative to the vertical and in this that the system further comprises a processing unit (19) receiving a measurement signal from each inclinometer (17, 17') and configured to trigger a door touch signal as a function of the measured inclination. Detection system according to claim 1, characterized in that the processing unit (19) determines an inclination differential between the two posts (9, 9') and is configured to trigger a door touch signal when the difference inclination between the two posts (9, 9') is greater than a predefined threshold. Detection system according to claim 2, characterized in that the predefined threshold is less than 7.5° and in particular equal to 5°. Detection system according to any one of claims 1 to 3, characterized in that the passage door (5) is equipped with at least one camera (21) configured to film the passage of a water vehicle (7), the processing unit (19) is configured to receive camera signals and to determine the direction of passage of the door (5). Detection system according to any one of claims 1 to 4, characterized in that one (9) of the posts of a passage door (5) comprises in its distal end portion an optical transmitter (23) and the other post (9') an optical receiver (25) in particular for measuring the passage time of the door in relation to a reference time. Detection system according to claim 5, characterized in that the emission beam (24) of the optical transmitter (23) has the shape of a fan with an emission angle greater than 30°, in particular equal to 60 °. Detection system according to claim 5 or 6, characterized in that the reception angle of the optical receiver (25) in a direction perpendicular to the post (9') is greater than 30°, in particular equal to 60°. Detection system according to any one of claims 1 to 7, characterized in that the passage door comprises an RFID reader (27) configured to detect during a passage an RFID chip carried by the nautical vehicle (7) or the sportsman maneuvering the latter. Detection system according to any one of claims 1 to 8, characterized in that the processing unit (19) is configured to receive a passage signal to synchronize the door touch measurement with the passage of a water vehicle (7). Sports course for white water competitions, characterized in that it comprises a detection system (1) according to any one of claims 1 to 9, the detection system comprising several passage doors (5) of a water vehicle (7), including a canoe or kayak.