TECHNIQUES FOR DETERMINING A VELOCITY OF A SPORT OBJECT

• US 20100069015A1
• Filed: 09/16/2009
• Published: 03/18/2010
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Entetrainer Oy
• Original Assignee: Entetrainer Oy
• Inventors: ILVAS, Lauri, Salmi, Timo, Tikander, Miikka, Salmi, Tomi, Luomaranta, Anssi
• Granted Patent: US 8,406,698 B2
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: A63B 2220/30 Speed
• CPC Class Codes: A63B 2220/62 Time or time measurement used for time reference, time stamp, master time or clock signal
• CPC Class Codes: A63B 2220/808 Microphones
• CPC Class Codes: A63B 2220/89 Field sensors, e.g. radar systems
• CPC Class Codes: A63B 2244/04 Bow shooting
• CPC Class Codes: A63B 47/008 Devices for measuring or verifying ball characteristics
• CPC Class Codes: A63B 69/00 Training appliances or apparatus for special sports training of parachutists B64D23/00
• CPC Class Codes: A63B 69/0026 for ice-hockey
• CPC Class Codes: A63B 69/385 for practising the serve
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A method for determining a velocity of an object (O), such as a ball, over a span length (SL) extending from a span start (SS) to a span end (SE). An audio signal (AS) is received by a mobile terminal'"'"'s (MT) microphone (MP). An approximate travel time (TT) for a traversal of the span length (SL) by the object (O) is determined, which act time comprises processing the audio signal (AS) and detecting a first shape (210) and a second shape (212) which respectively correspond to an approximate start time (T1) and approximate end time (T2) of the traversal, and determining the approximate travel time (TT) based on the detected first shape (210) and second shape (212). The object'"'"'s velocity is determined based on the span length (SL) and approximate travel time (TT). The velocity may be determined by the mobile terminal or by an external server.

Claims

1. A method for determining a velocity of an object, comprising:

receiving an audio signal by at least one microphone operatively coupled to a mobile terminal, wherein the mobile terminal is attached to a wireless network;

processing the received audio signal, wherein the processing of the audio signal comprises converting the audio signal to a series of audio samples each of which has an intensity value and duration, and conveying the series of audio samples to a velocity calculation unit;

performing the following steps by the velocity calculation unit;

determining a span length to be traversed by the object, wherein the span length extends from a span start to a span end;

determining an approximate travel time for a traversal of the span length from the span start to the span end by the object, wherein the determination of the approximate travel time comprises;

processing the series of audio samples and detecting a first shape and a second shape which respectively correspond to an approximate start time and approximate end time of the traversal;

determining the approximate travel time by determining a combined duration of the audio samples between the detected first shape and second shape;

determining the velocity of the object based on the span length and approximate travel time; and

conveying information on the velocity of the object from the velocity calculation unit to a user interface of the mobile terminal; and

outputting the velocity of the object via the user interface of the mobile terminal.

2. A method according to claim 1, wherein the determination of the velocity comprises determining an average velocity and applying a correction to the average velocity to determine an initial velocity.

3. A method according to claim 1, wherein the determination of the velocity comprises determining an initial velocity by applying the span length and travel time to a function or lookup table.

4. A method according to claim 1, wherein the determination of the travel time comprises compensating for unequal distances of the microphone from the span start and span end.

5. A method according to claim 1, wherein the detection of the first shape and/or second shape comprises detecting a sample whose intensity exceeds a predetermined threshold.

6. A method according to claim 1, wherein the detection of the first shape and/or second shape comprises detecting a group of consecutive samples wherein the group'"'"'s last sample has an intensity which exceeds the intensity of the group'"'"'s first sample by a predetermined margin.

7. A method according to claim 1, wherein the detection of the first shape and/or second shape comprises:

maintaining at least two sliding windows A and B which partially overlap one another;

detecting a presence of the first shape and/or second shape within the at least two partially overlapping windows by determining that f_A(INT) over one of the sliding windows exceeds f_B(INT) over the other sliding window by a predefined margin, wherein INT represents the audio signal'"'"'s intensity or its derivative, while f stands for a statistically representative function; and

searching for an onset of the audio signal within the at least two partially overlapping windows.

8. A method according to claim 1, further comprising skipping a predetermined number of samples or milliseconds after the detected first shape and/or second shape before detecting a subsequent shape.

9. A method according to claim 1, further comprising rejecting the series of audio samples if the combined duration of the audio samples between the detected first shape and second shape is lower than a predetermined minimum time.

11. A software program product, executable in a mobile terminal, wherein execution of the software program product in the mobile telephone causes the mobile terminal to carry out the acts defined in claim 1.

10. A mobile terminal, comprising:

means for attaching to a wireless network;

a software program product, wherein execution of the software program product in the mobile terminal causes the mobile terminal to carry out the following acts;

receiving an audio signal by a microphone operatively coupled to the mobile terminal;

processing the received audio signal, wherein the processing of the audio signal comprises converting the audio signal to a series of audio samples each of which has an intensity value and duration and wherein the series of audio samples extend over a travel time for a traversal of a span length from a span start to a span end by an object;

transmitting the series of audio samples via the wireless network to a server;

receiving information on a velocity of the object from the server; and

visually and/or audibly outputting the velocity of the object.

12. A server system operatively coupled to a wireless network which supports bidirectional communication between the server and a mobile terminal, the server comprising;

means for determining a span length to be traversed by an object, wherein the span length extends from a span start to a span end;

means for receiving from the mobile terminal a series of audio samples each of which has an intensity value and duration and wherein the series of audio samples extend over a travel time for a traversal of the span length by the object;

time-determination means for determining an approximate travel time for a traversal of the span length from the span start to the span end by the object, wherein the time-determination means comprises;

means for processing the series of audio samples and for detecting a first shape and a second shape which respectively correspond to an approximate start time and approximate end time of the traversal;

means for determining the approximate travel time by determining a combined duration of the audio samples between the detected first shape and second shape;

means for determining the velocity of the object based on the span length and approximate travel time; and

means for transmitting information on the velocity of the object from the server to the mobile terminal.

13. A server system according to claim 12, further comprising:

community maintenance means for registering, logging in and keeping records of mobile terminal users as community members, wherein the record of a community member at least indicates an identity, sport and top velocity obtained by the community member;

advertising means for selecting and delivering advertisements to community members, wherein said selection of advertisements is based at least on the respective sport of the community member.

14. A server system according to claim 13, wherein the community maintenance means comprises:

means for registering and logging in a plurality of trusted users;

means for receiving a confirmation from one or more trusted user in respect of a velocity attained by a community member;

means for displaying velocities attained by community members to other community members; and

means for indicating whether a velocity attained by a community member has been confirmed by at least one trusted community member.