RU2776497C2 - System for automatic determination of “out of play” position in football - Google Patents

Abstract

FIELD: sports.

SUBSTANCE: invention relates to the field of sports; it is intended for use in refereeing of football matches. A system for automatic determination of an “out of play” position in football is characterized in that flags of linear referees are equipped with radio signal transmitters for communication with computers processing video signals coming from video cameras located above the middle of each of halves of a football field, and a handle of the linear referee flag is equipped with a button for switching on a radio signal at the moment of passing a ball to a player presumably being in the “out of play” position for sending this radio signal to the computer implementing an algorithm for the determination of the “out of play” position, when calculating in real time the minimum distance from each player of both teams being on this half of the field to a face line, as well as taking into account an algorithm for changing halves of the field by teams after the break and a “passive offside” position. Thus, an “assessment” function allowing the determination of the “out of play” position is completely delegated to the computer, which is part of the system.

EFFECT: proposed system for automatic determination of an “out of play” position, in combination with a ubiquitous system of video assistant referee (VAR), will allow for minimization referee’s mistakes in football matches, which, in turn, will affect an increase in entertainment and attractiveness of football.

1 cl, 3 dwg

Description

The automatic offside detection system belongs to the field of sports and is intended for use in refereeing football matches.

According to the Laws of the Game of Football, a player is in an offside position if he is closer to the opponent's goal line than the ball and the penultimate player of the opponent, including the goalkeeper. In FIG. 1 rightmost red circle denotes a player of the attacking team who is in an offside position.

One of the duties of the linesman (in the modern interpretation - the assistant chief arbiter) is to determine offside. The difficulty of fixing offside (and related refereeing errors) lies in the fact that the linesman must immediately determine the beginning of the transfer of the ball to the player, presumably in the offside position, and assess the position of this player relative to other players and the end line of this half of the football field . It is the "evaluative" function that presents the greatest difficulty, since human vision is not able to determine the distance between the players with sufficient accuracy. In addition, the visual assessment is influenced by the position of the linesman himself (angle) and the presence of players blocking his view.

The proposed system allows you to transfer the "evaluative" function to the computer, and the line judge can only record the moment of passing the ball. The system involves the use of the following equipment:

- two video cameras located in the center over their own half of the field so that each of them covers the "look" of the nearest half of the field in its entirety. An exemplary arrangement of the chambers is shown in Fig. one;

- line judge's flag, equipped with a transmitter for communication with the operator's computer. The transmitter signal is turned on using the button on the flag handle (this equipment has already been developed and is now used to connect the linesman with the chief arbiter);

- two computers for processing the video signal from the cameras and calculating the required distances (each for its own half of the field).

Before the start of the game, operators who monitor the operation of the system enter the colors of the team uniforms in the program dialog box, for example:

black and white = blue

green = red.

This is done for the simplicity of the system, since it excludes the creation of a database containing all the various forms of all commands.

The video signal from each camera is transmitted to its own computer for processing. The essence of processing is as follows - the images of the players are converted into the corresponding colored (red and blue) rectangles; however, images of the goalkeeper and referees are excluded, since the colors of their uniforms differ from the colors of the uniforms of field players, and they themselves are not needed to determine the offside position.

The system operates in accordance with the algorithm shown in Fig. 2.

T ₁ and T ₂ - the time of the end of the first and second halves (ie 45 and 90 minutes), respectively, or the time of the end of extra halves (ie 15 and 30 minutes).

S ₁ - a signal from the line judge about the alleged offside.

S ₂ - repeated signal from the linesman in case of a "passive" offside.

t _s1 and t _s2 - time of receipt of signals S ₁ and S ₂ respectively.

t _a and t _b - stoppage time for the first and second halves, respectively.

Let us analyze the operation of the algorithm for the right half of the field (Fig. 1). Before the start of the game, the operator enters into the program the value of Τ ₁ and T ₂ - the end time of the first and second halves (45 minutes and 90 minutes), respectively. If the game ended in a draw and it is required to determine the winner with the help of extra halves, then the end time of the extra halves is entered, i.e. 15 minutes. and 30 min. Before the end of the first, second and extra halves, the chief judge determines the number of compensated minutes, which are also entered by the operator (t _a and t _b ).

The video signal processing unit works according to the method described above. The “evaluative” function of the program begins with a cycle of determining H _{c min} , H _{k min} . The variable H _{c min} means the minimum distance from the “extreme” blue player to the end line in this half of the field. The variable H _{to min} also means only for the red player. In FIG. 3 shows a method for determining H _{c min} , H _{k min} . Two colored movable cursors: "C" (blue - defense) and "K" (red - attack) in real time track the position of the "extreme", relative to the front line of this half of the field, the players of each team. When moving a player to the right of the corresponding cursor, the latter "sticks" to this player. The distance between each of the cursors and the front line is discrete, i.e. for each position at a given point the "field" is known. Therefore, no calculations are required.

Further in the program follows the cycle of the report of time for each half. If the condition t>Τ ₁ +t _a is met, which corresponds to the end of the first main or additional half, a 15-minute delay block is activated, indicating a break between the halves. This is followed by a clock cycle for the second half or extra half. If the condition t>T ₂ +t _b is met, which corresponds to the end of the second main or extra time, the program ends.

If at the time of the clock cycle of any half, the signal S ₁ is received from the linesman, this will mean that he pressed the button on his flag at the moment the ball was passed to the player of the attacking team, presumably being in an offside position in this half of the field . In this case, the program proceeds to compare H _{with min} and H _{k min} , respectively, for each of the halves. Those. the fulfillment of the condition H _{k min} <Н _{с min} for the first main or additional half or H _{k min} <Н _{с min} for the second main or additional half is checked. Depending on the result of this comparison, the program either returns to the beginning of the cycle for determining H _{with min} and H _{k min} (no offside), or, passing through the two-second delay element, issues an offside message, which is sent to the main arbiter in the form of an audio signal to his headset , and to various display devices in the stadium (scoreboard, billboards around the field) lasting 5 seconds (approximate time).

The two-second delay element is necessary for the case of a “passive” offside position. A “passive” offside occurs when a player, although he is in an “offside” position, does not affect the development of the attack (does not touch the ball, does not block the view of the opponent's goalkeeper, etc.). If after the first pressing of the button on the flag (signal S ₁ ) the line judge has a position of "passive" offside (it takes 1-2 seconds for an experienced judge to visually assess this), or the ball for some reason did not reach the player, presumably in the position “outside the game”, the line judge repeatedly presses the button on the flag (signal S ₂ ). In this case, the condition t _s2 -t _s1 <2s is checked. If this condition is met, an offside message is not generated. a “passive” offside position has arisen, the program returns to its original state (definition of H _{with min} and H _{k min} ). If the condition is not met, i.e. the second signal came after two seconds, then the primary offside message is generated in the above way.

For the other half of the football field, the second similar part of the system works in the same way, with the only difference that H _{c min} and H _{k min} in the comparison blocks for each half are interchanged.

Thus, the system for automatically determining the offside position achieves the technical result that the assistant chief referee of a football match (line judge) does not need to simultaneously determine the moment of passing the ball to the player of the attacking team, presumably in the offside position, and evaluate the position of this player relative to the players of the defending team, since this “evaluative” function is completely transferred to the computer that is part of the system, and the line judge only needs to fix the moment of passing the ball to the player, presumably in the “offside” position.

This system, in combination with the video assistance to the arbiter (VAR) system recently used by FIDE and a number of national federations, will allow minimizing the so-called. the human factor in refereeing football matches, which in turn will increase the entertainment and attractiveness of football.

Claims (1)

A system for automatically determining the offside position in football, characterized by the fact that with the help of flags of line judges equipped with radio signal transmitters for communication with computers that process video signals from video cameras located above the middle of each of the halves of the football field, and the handle of the flag of the linear the referee is equipped with a button to turn on the radio signal at the moment the ball is passed to the player, presumably in the offside position, to send this radio signal to the computer, which implements the algorithm for determining the offside position when calculating in real time the minimum distance from each player of both teams, located on this half of the field, to the end line, as well as taking into account the algorithm for changing half of the field by teams after the break and the position of "passive offside"; thus, the "evaluative" function, which allows to determine the position of "offside", is completely transferred to the computer that is part of the system.

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