Techniques for determining a velocity of a sport object

• US 8,406,698 B2
• Filed: 09/16/2009
• Issued: 03/26/2013
• Est. Priority Date: 09/17/2008
• Status: Expired due to Fees

• Current Assignee: Entetrainer Oy
• Original Assignee: Entetrainer Oy
• Inventors: Ilvas, Lauri, Luomaranta, Anssi, Salmi, Timo, Salmi, Tomi, Tikander, Miikka
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): Redmann, Gregory J
• Application Number:
  US12/561,061
• Publication Number:
  US 20100069015A1
• Time in Patent Office: 1,287 Days
• Field of Search: 455/67.11, 734/91
• US Class Current: 455/67.11
• 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 digital audio samples each of which has a predetermined intensity value and duration, and conveying the series of digital 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 digital 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;

wherein the detection of the first shape and/or second shape comprises detecting a digital audio sample whose intensity exceeds a predetermined threshold or a group of consecutive digital audio samples wherein the group'"'"'s last digital audio sample has an intensity which exceeds the intensity of the group'"'"'s first digital audio sample by a predetermined margin;

determining the approximate travel time by determining a combined duration of the digital audio samples between the detected first shape and second shape, wherein the determination of the approximate travel time comprises determining the number and duration of digital 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:

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 fA(INT) over one of the sliding windows exceeds fB(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.

6. 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.

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

8. A method according to claim 1, wherein the step of detecting a first shape and a second shape which respectively correspond to an approximate start time and approximate end time of the traversal further comprises detecting the first shape and the second shape among the series of digital audio samples.

9. A system, comprising a mobile terminal and a velocity calculation unit, wherein the mobile terminal comprises:

an attaching device configured to attach to a wireless network; and

a memory storing 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 digital audio samples each of which has a predetermined intensity value and duration and wherein the series of digital 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; and

transmitting the series of digital audio samples via the wireless network to the velocity calculation unit,

wherein the velocity calculation unit is configured to determine an approximate travel time for the traversal of the span length by the object, wherein the determination of the approximate travel time comprises;

processing the series of digital 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, wherein the detection of the first shape and/or second shape comprises detecting a digital audio sample whose intensity exceeds a predetermined threshold or a group of consecutive digital audio samples wherein the group'"'"'s last digital audio sample has an intensity which exceeds the intensity of the group'"'"'s first digital audio sample by a predetermined margin;

determining the approximate travel time by determining a combined duration of the digital audio samples between the detected first shape and second shape, wherein the determination of the approximate travel time comprises determining the number and duration of digital 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 to the mobile terminal,

wherein execution of the software program product in the mobile terminal further causes the mobile terminal to receive information on the velocity of the object and to visually and/or audibly output the velocity of the object.

10. The system according to claim 9, further comprising:

a community maintenance device configured to register, log in and keep 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; and

an advertising device configured to select and deliver advertisements to community members, wherein said selection of advertisements is based at least on the respective sport of the community member.

11. The system according to claim 10, wherein the community maintenance device comprises:

a registering device configured to register and log in a plurality of trusted users;

a receiving device configured to receive a confirmation from one or more trusted user in respect of a velocity attained by a community member;

a displaying device configured to display velocities attained by community members to other community members; and

a indicating device configured to indicate whether a velocity attained by a community member has been confirmed by at least one trusted community member.

12. The system according to claim 9, wherein the software program product stored in the memory is a downloadable software program product.

13. The system according to claim 9, wherein the velocity calculation unit is located in the mobile terminal.

14. The system according to claim 9, wherein the velocity calculation unit is located in a server external to the mobile terminal.

15. The system according to claim 9, wherein the velocity calculation unit is configured to detect the first shape and the second shape among the series of digital audio samples.