CN201353415Y

CN201353415Y - Tennis ball touching-the-net judgment device

Info

Publication number: CN201353415Y
Application number: CNU2008202285424U
Authority: CN
Inventors: 王保金; 孙建; 梁建强; 蒋庄德; 赵玉龙
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2008-12-30
Filing date: 2008-12-30
Publication date: 2009-12-02
Anticipated expiration: 2018-12-30

Abstract

The utility model relates to a tennis ball touching-the-net judgment device, which comprises a closed container 3. A suspension body 13 and a holding hand 2 matched with the suspension body 13 are configured at the top of the closed container 3. An MEMS acceleration sensor 5 and a processing circuit 6 are encapsulated in the closed container 3. The signal output end of the MEMS acceleration sensor 5 is connected with the signal input end of the processing circuit 6. The signal output end of the processing circuit 6 is led out by a conducting wire 4. The entire device is held at the central part of a net string. When the tennis ball touches the net, the net string 1 vibrates. After the MEMS acceleration sensor 5 senses the acceleration signal caused by the vibration, the sensor outputs a voltage signal. After the voltage signal is processed by the processing circuit 6, the processed voltage signal drives an alarm indicating device 12 to alarm through a buzzer and an indicating lamp that the tennis ball touches the net. The utility model has the advantages of small volume, light weight, high accuracy, low cost, low power consumption and high stability.

Description

Tennis net judgment means

Technical field

The utility model relates to a kind of athletic sports appliance, the high accuracy net judgment means in particularly a kind of tennis.

Background technology

In tennis tournament, the accurate judgement of net is a problem that is difficult to solution always.Traditional determination methods is naked-eye observation, but the method exist the degree of accuracy not high, have shortcomings such as personal safety hidden danger.Sometimes net can cause obviously rocking of net, the judge can easily determine server's foul hit like this, but tennis is slight contacting with net sometimes, and the velocity ratio of tennis is very fast, can reach 244.6Km/h when the fastest, this has surpassed people's response speed from far away, and slightly rocking of therefore causing netting is difficult to discover, so erroneous judgement usually occurs, reveal and declare.

In international blue-ribbon event, generally adopt high-speed camera that heat is recorded a video, the form of taking playing back videos to determine when the dispute ball occurring is come auxiliary judgement, but this covering device costs an arm and a leg, and domestic other match of general level also is not equipped with.

Summary of the invention

The purpose of this utility model is to overcome the shortcoming of traditional method of discrimination, proposes a kind of tennis net judgment means, can satisfy the needs of real racetrack, and has the reliability height, uses characteristics such as simple and easy to carry.

The technical solution of the utility model is achieved in that tennis net judgment means, comprise a closed container 3, configuration one hanging body 13 and holding handle with matching 2 outside the top of closed container 3, be packaged with MEMS acceleration transducer 5 and treatment circuit 6 in the closed container 3, the signal output part of MEMS acceleration transducer 5 links to each other with the signal input part of treatment circuit 6, and the signal output part of treatment circuit 6 is drawn by lead 4.

Treatment circuit 6 is made up of signal conditioning circuit module and warning indicating device 12, and wherein signal conditioning circuit is made up of comparison module 7, amplification module 8, shroud module 9, power supply 10 and overload protecting circuit 11.MEMS acceleration transducer 5 signal output parts link to each other with the signal input part of comparison module 7, and comparison module 7 outputs are connected with the input of amplification module 8, and the amplifying signal of output directly links to each other with warning device 12 by behind the overload protecting circuit 11.The both positive and negative polarity of power supply 10 is connected with the positive and negative feeder ear of the LM311 of AD620 respectively.

Warning indicating device 12 is made up of buzzer and indicator lamp.

Whole device takes mechanical grip to be installed in net backguy 1 middle part, after the tennis net, can cause the vibration of net backguy 1, after being installed in MEMS acceleration transducer 5 in the net backguy 1 and experiencing the acceleration signal that vibration causes, just output voltage signal, this signal is handled by treatment circuit 6, utilizes the signal after handling to drive warning indicating device 12 then, carries out net by buzzer and indicator lamp and reports to the police.

The net alarm electronics that the utility model proposes based on mems accelerometer has that volume is little, in light weight, the degree of accuracy is high, cost is low, a low-power consumption, stable advantages of higher, and has certain portability.

Description of drawings

Fig. 1 is a sensing element structure principle chart of the present utility model.

Fig. 2 is a schematic block circuit diagram of the present utility model.

Fig. 3 is the block diagram of signal processing circuit 6.

Fig. 4 is the circuit diagram of signal processing circuit 6.

The specific embodiment

Below in conjunction with accompanying drawing structural principle of the present utility model and operation principle are elaborated.

Referring to Fig. 1, sensing element of the present utility model comprises a closed container 3, configuration one hanging body 13 and holding handle with matching 2 outside the top of closed container 3, be packaged with MEMS acceleration transducer 5 and treatment circuit 6 in the closed container 3, the signal output part of MEMS acceleration transducer 5 links to each other with the signal input part of treatment circuit 6, and the signal output part of treatment circuit 6 is drawn by lead 4.

During use, net backguy 1 is placed between hanging body 13 and the holding handle 2, turn holding handle 2 is clamped in the net backguy 1 whole sensing element, in order to guarantee the reliability of clamping, adopt mechanical spiral to clamp, by rotation holding handle 2, just can install and dismounting whole sensing element easily.Consider sensitiveness and accuracy, adopt symmetric arrangement, whole sensing element is installed in the net backguy 1 at middle part.

Referring to Fig. 2, circuit of the present utility model comprises a MEMS acceleration transducer 5, the signal output part of MEMS acceleration transducer 5 links to each other with the signal input part of treatment circuit 6, and the signal output part of treatment circuit 6 is led to the signal input part of warning indicating device 12 by lead 4.

Its operation principle is: when the tennis net, cause the vibration of net, after MEMS acceleration transducer 5 is experienced vibration, just output voltage signal C, C is handled by treatment circuit 6 to this signal, signal D after utilize handling triggers warning indicating device 12, differentiates and indicates net by buzzer and indicator lamp.

Referring to Fig. 3,4, entire process circuit 6 is made up of signal conditioning circuit module and warning indicating device 12, and wherein signal conditioning circuit is made up of comparison module 7, amplification module 8, shroud module 9, power supply 10 and overload protecting circuit 11.MEMS acceleration transducer 5 signal output parts link to each other with the signal input part of comparison module 7, and comparison module 7 outputs are connected with the input of amplification module 8, and the amplifying signal of output directly links to each other with warning device 12 by behind the overload protecting circuit 11.The both positive and negative polarity of power supply 10 is connected with the positive and negative feeder ear of instrument amplifier AD620, LM311 respectively.

For the accuracy that prevents that the interfering signal influence from judging, need a comparison module 7 to remove the influence of interference, comparison module 7 adopts instrument amplifier LM311, and adjustable resistance Rf can be provided with the size of disturbing reference signal.Because the voltage signal of sensor output is less, so need be to its amplification so that drive follow-up warning device, amplification module 8 employing instrument amplifier AD620.Net in the batting process behind the tennis service does not need to warn, and is in resting state so need a shroud module to make in the batting process of warning device after service, can utilize K switch 1 to realize this function.Whole supply unit 10 in order to prevent instantaneous excessive signal corruption circuit devcie and warning indicating device 12, needs an overload protecting circuit 11 by positive and negative 3 volts of DC power supplies, utilizes the Zener diode in parallel with warning device can realize this function.

Warning indicating device 12 is made up of buzzer and indicator lamp.

Claims

1, tennis net judgment means, it is characterized in that, comprise a closed container (3), configuration one hanging body (13) and holding handle with matching (2) outside the top of closed container (3), be packaged with MEMS acceleration transducer (5) and treatment circuit (6) in the closed container (3), the signal output part of MEMS acceleration transducer (5) links to each other with the signal input part of treatment circuit (6), and the signal output part of treatment circuit (6) is drawn by lead (4).

2, according to the said tennis net of claim 1 judgment means, it is characterized in that, treatment circuit (6) is made up of signal conditioning circuit and warning indicating device (12), wherein signal conditioning circuit is by comparison module (7), amplification module (8), shroud module (9), power supply (10) and overload protecting circuit (11) are formed, MEMS acceleration transducer (5) signal output part links to each other with the signal input part of comparison module (7), comparison module (7) output is connected with the input of amplification module (8), the amplifying signal of output is by behind the overload protecting circuit (11), directly link to each other with warning device (12), the both positive and negative polarity of power supply (10) respectively with instrument amplifier AD620, the positive and negative feeder ear of LM311 connects; Warning indicating device (12) is made up of buzzer and indicator lamp.