WO2006066373A1 - Strain gauge for measuring surfboard speed - Google Patents

Strain gauge for measuring surfboard speed Download PDF

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Publication number
WO2006066373A1
WO2006066373A1 PCT/BR2005/000245 BR2005000245W WO2006066373A1 WO 2006066373 A1 WO2006066373 A1 WO 2006066373A1 BR 2005000245 W BR2005000245 W BR 2005000245W WO 2006066373 A1 WO2006066373 A1 WO 2006066373A1
Authority
WO
WIPO (PCT)
Prior art keywords
measuring
surfboard
speed
strain gauge
stem
Prior art date
Application number
PCT/BR2005/000245
Other languages
French (fr)
Inventor
Salvador Francisco Tirloni
Avelino Arantes Bastos
Original Assignee
Salvador Francisco Tirloni
Avelino Arantes Bastos
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Salvador Francisco Tirloni, Avelino Arantes Bastos filed Critical Salvador Francisco Tirloni
Publication of WO2006066373A1 publication Critical patent/WO2006066373A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B49/00—Arrangements of nautical instruments or navigational aids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/02—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring forces exerted by the fluid on solid bodies, e.g. anemometer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B32/00—Water sports boards; Accessories therefor
    • B63B32/70—Accessories not specially adapted for a particular type of board, e.g. paddings or buoyancy elements

Definitions

  • This report describes a patent concerning a device for measuring the speed of a surfboard or similar related to the water using the principle of deformations measurement by using strain gauges.
  • Patent PIO 106598-0 describes a telemetrical system for surfboard and correlatives.
  • Patents can be found describing systems for measuring boards' speed.
  • GB2270504 describes a speed measuring system in knots, concerning a sailboard and applying the Venturi's tube principle.
  • Patent DE19718917 describes a system that measures the board's speed by means of an optical system which detects the bubbles generated during the flow; the system, then, sends the data to an interface inside the wrist watch used by the surfer.
  • Patent BR PI 0300620-4 published by WIPO under number
  • WO2004076990 describes a surfboard measuring speed system using a spherical lobe fixed to one of the ends of a stem.
  • the water pressure force actuating on the sphere lobe makes it and the stem swing related to a knee joint at the other end of the stem, enabling potentiometers to correlate the stem's displacement with the board's speed.
  • the device hereby described for measuring the speed of a surfboard differs from the above mentioned ones by presenting a system that measures the fluid flow speed related to a board or vessel by using string gauges. It has a stem with square cross-section perpendicularly affixed to the surfboard hull having a spherical lobe at the other end. The measurements are based on the solid stem's fibers expansion and contraction measuring principle and the stem's deformation values, measured by strain gauges, are digitally processed and transformed into parameters equal to the speed and the processor sending values corresponding to the fluid relative velocity related to the spherical lobe.
  • Figure 1 is a side view of the measuring system affixed to the board hull showing the board(l) and the measuring system(2).
  • Figure 2 is the measuring system(2) detailed view showing board(l), stem(3), sphere lobe(4) and strain gauges(5).
  • the device has the function of receiving the relative velocity of the board(l) related to the fluid, generally water.
  • the device comprises a square cross-section stem(3) coated with a material providing a cylindrical external shape to it so as to undergo the lesser fluid flow resistance.
  • One of the ends of the stem(3) is affixed to the board(l) hull while the other holds the sphere lobe(4).
  • Four strain gauges(5) are placed at approximately half the height of the stem(3), one on each stem's face. The displacement water force applied on the sphere lobe(4) bends the stem(3) causing a deformation that can be measured by transducers like strain gauges(5).
  • the strain gauges(5) are perpendicularly positioned one related to the other so as to form a disposition known as charge cell using Wheatstone bridge type electrical connection diagrams. This configuration allows simultaneously measuring the compressed fibers and the extended ones due to the bending strength of the stem(3) which values after processing the signal and being added of the time variable will result in speed and displacement of the board(l).
  • the strain gauges(5) measure the stem's longitudinal and transversal deformations related to the board(l); the achieved vectors, perpendicular among each other, are processed so as to achieve a resultant value.
  • the processor searches, in a previously established table, for a value corresponding to the board's displacement speed.
  • the measuring system(2) is previously calibrated in a laboratory where known measuring devices measure the water speed related to the board and simultaneously the strain gauges measure the deformations on the stem(3). This calibration table is added to the measuring system(2) micro controller processor.
  • the obtained relative velocity value is then sent through radio frequency to fix digital stations and/or to a display on the surfer wrist.
  • the sphere lobe(4) that offers resistance to the water flow is an outstanding characteristic because the spherical shape offers equal resistance to the flow whichever is the water flow direction related to the board. So, it is possible to measure the board's displacement speed related to the water whichever the direction is.
  • the measuring system hereby described was said to be affixed to a surfboard only as an example of a real application and for a better understanding of the inventive act. It can be used, however, in other equipments and vehicles sliding on water, in the air or on any other fluid.
  • the measuring system hereby described may be assembled to equipments such as windsurf, kite surf, wakeboard or body board, boats or any other navigable vehicles.

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  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Testing Or Calibration Of Command Recording Devices (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

Strain gauge for measuring surfboard speed is a device for measuring the speed of a surfboard or similar related to the water using the strain gauge deformation measuring principle. The device comprises a stem(3) where one of its ends is affixed to the surfboard(l) hull and the other one holds a spherical lobe(4) so that when the surfboard(l) displaces, the water strength force on the spherical lobe(4) makes the stem(3) to bend causing a deformation which is measured by the strain gauges(5) and after that processed in order to get the relative velocity values.

Description

STRAIN GAUGE FOR MEASURING SURFBOARD SPEED FIELD OF THE INVENTION
This report describes a patent concerning a device for measuring the speed of a surfboard or similar related to the water using the principle of deformations measurement by using strain gauges.
BACKGROUND OF THE INVENTION
Techniques have been developed for measuring the speed of vessels related to the water, but most of them are performed in laboratories.
In a laboratory the body stays still while the fluid flows around it. The measuring equipments used in these conditions only allow obtaining measurements to evaluate the body's hydrodynamic shape, resistance areas to the movement and friction losses.
In real conditions, measurements are not so simple and precise. There are only a few measuring equipments that when affixed to the surfboard do not significantly interfere on its performance, on the displacement resistance or even the surfer concentration. Patent PIO 106598-0 describes a telemetrical system for surfboard and correlatives.
It presents functional features and block diagrams for acquisition, transmission and storage the parameters with the data.
Other patents can be found describing systems for measuring boards' speed. Patent
GB2270504 describes a speed measuring system in knots, concerning a sailboard and applying the Venturi's tube principle. Patent DE19718917 describes a system that measures the board's speed by means of an optical system which detects the bubbles generated during the flow; the system, then, sends the data to an interface inside the wrist watch used by the surfer. Patent BR PI 0300620-4 published by WIPO under number
WO2004076990, describes a surfboard measuring speed system using a spherical lobe fixed to one of the ends of a stem. The water pressure force actuating on the sphere lobe makes it and the stem swing related to a knee joint at the other end of the stem, enabling potentiometers to correlate the stem's displacement with the board's speed.
SUMMARY OF THE INVENTION
The device hereby described for measuring the speed of a surfboard differs from the above mentioned ones by presenting a system that measures the fluid flow speed related to a board or vessel by using string gauges. It has a stem with square cross-section perpendicularly affixed to the surfboard hull having a spherical lobe at the other end. The measurements are based on the solid stem's fibers expansion and contraction measuring principle and the stem's deformation values, measured by strain gauges, are digitally processed and transformed into parameters equal to the speed and the processor sending values corresponding to the fluid relative velocity related to the spherical lobe.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view of the measuring system affixed to the board hull showing the board(l) and the measuring system(2). Figure 2 is the measuring system(2) detailed view showing board(l), stem(3), sphere lobe(4) and strain gauges(5).
DESCRIPTION OF THE PREFERRED EMBODIMENT
Concerning the device hereby described it has the function of receiving the relative velocity of the board(l) related to the fluid, generally water. The device comprises a square cross-section stem(3) coated with a material providing a cylindrical external shape to it so as to undergo the lesser fluid flow resistance.
One of the ends of the stem(3) is affixed to the board(l) hull while the other holds the sphere lobe(4). Four strain gauges(5) are placed at approximately half the height of the stem(3), one on each stem's face. The displacement water force applied on the sphere lobe(4) bends the stem(3) causing a deformation that can be measured by transducers like strain gauges(5). The strain gauges(5) are perpendicularly positioned one related to the other so as to form a disposition known as charge cell using Wheatstone bridge type electrical connection diagrams. This configuration allows simultaneously measuring the compressed fibers and the extended ones due to the bending strength of the stem(3) which values after processing the signal and being added of the time variable will result in speed and displacement of the board(l).
The strain gauges(5) measure the stem's longitudinal and transversal deformations related to the board(l); the achieved vectors, perpendicular among each other, are processed so as to achieve a resultant value. The processor searches, in a previously established table, for a value corresponding to the board's displacement speed. The measuring system(2) is previously calibrated in a laboratory where known measuring devices measure the water speed related to the board and simultaneously the strain gauges measure the deformations on the stem(3). This calibration table is added to the measuring system(2) micro controller processor. The obtained relative velocity value is then sent through radio frequency to fix digital stations and/or to a display on the surfer wrist.
The sphere lobe(4) that offers resistance to the water flow is an outstanding characteristic because the spherical shape offers equal resistance to the flow whichever is the water flow direction related to the board. So, it is possible to measure the board's displacement speed related to the water whichever the direction is.
The measuring system hereby described was said to be affixed to a surfboard only as an example of a real application and for a better understanding of the inventive act. It can be used, however, in other equipments and vehicles sliding on water, in the air or on any other fluid. The measuring system hereby described may be assembled to equipments such as windsurf, kite surf, wakeboard or body board, boats or any other navigable vehicles.

Claims

1 - STRAIN GAUGE FOR MEASURING SURFBOARD SPEED is a device for measure the speed of a surfboard(l) related to the water, characterized by measuring the speed by way of measuring the deformations in a beam using strain gauges(5); 2 - STRAIN GAUGE FOR MEASURING SURFBOARD SPEED according to claim 1, characterized by being the beam a stem(3) perpendicular to the water flow having one of its ends affixed to the surfboard(l) hull and the other one holding a spherical lobe(4);
3 - STRAIN GAUGE FOR MEASURING SURFBOARD SPEED according to claim 1, characterized by having four strain gauges(5) which are placed at half the height of stem(3) and on each face of its square cross-section;
4 - STRAIN GAUGE FOR MEASURING SURFBOARD SPEED according to claim 1, characterized by having two strain gauges(5) placed at half the height of stem(3) on faces perpendicular among each other;
5 - STRAIN GAUGE FOR MEASURING SURFBOARD SPEED according to claim 1, characterized by being the beam's deformations values measured by the strain gauges(5) digitally processed, compared with an existing calibration table in the processor's program and the processor sending values correspondents to the fluid relative velocity related to the spherical lobe(4);
6 - STRAIN GAUGE FOR MEASURING SURFBOARD SPEED according to claim 5, characterized by being the obtained relative velocity values sent through radio frequency to fix digital stations.
PCT/BR2005/000245 2004-12-20 2005-11-28 Strain gauge for measuring surfboard speed WO2006066373A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BRPI0405808-9 2004-12-20
BRPI0405808-9A BRPI0405808A (en) 2004-12-20 2004-12-20 surfboard speed measurement by extensometers

Publications (1)

Publication Number Publication Date
WO2006066373A1 true WO2006066373A1 (en) 2006-06-29

Family

ID=36601299

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/BR2005/000245 WO2006066373A1 (en) 2004-12-20 2005-11-28 Strain gauge for measuring surfboard speed

Country Status (2)

Country Link
BR (1) BRPI0405808A (en)
WO (1) WO2006066373A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2930307A1 (en) * 1979-07-26 1981-02-19 Grapho Metronic Gmbh & Co Cockpit instrument giving sailing boat speed w.r.t. wind - uses mathematical combination of damped readings of speed and angle
FR2545220A1 (en) * 1983-04-29 1984-11-02 Giraud Patrick Multi-purpose indicator (speed, mileage, dagger-board angle, etc.), for sail boards and other craft
US5062378A (en) * 1989-11-16 1991-11-05 Bateman Jess R Hydrofoil and surfboard type assembly
WO2004076990A2 (en) * 2003-02-25 2004-09-10 Salvador Francisco Tirloni Surfing parameters gauge and transfer apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2930307A1 (en) * 1979-07-26 1981-02-19 Grapho Metronic Gmbh & Co Cockpit instrument giving sailing boat speed w.r.t. wind - uses mathematical combination of damped readings of speed and angle
FR2545220A1 (en) * 1983-04-29 1984-11-02 Giraud Patrick Multi-purpose indicator (speed, mileage, dagger-board angle, etc.), for sail boards and other craft
US5062378A (en) * 1989-11-16 1991-11-05 Bateman Jess R Hydrofoil and surfboard type assembly
WO2004076990A2 (en) * 2003-02-25 2004-09-10 Salvador Francisco Tirloni Surfing parameters gauge and transfer apparatus

Also Published As

Publication number Publication date
BRPI0405808A (en) 2006-09-05

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