News Column

Researchers Submit Patent Application, "Apparatus to Measure the Power Expended in Propelling a Vessel on Water", for Approval

September 10, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors PAPE, TRAVIS (DURHAM, NC); HAMANN, JOHN (GULF STREAM, FL), filed on April 26, 2014, was made available online on August 28, 2014.

The patent's assignee is Velocomp, Llc.

News editors obtained the following quote from the background information supplied by the inventors: "In sports training, it is desirable to measure performance indications of an athlete, such as the power produced and the total energy expended. As athlete training continues to become more and more sophisticated, some training is conducted indoors under controlled conditions, where typically large or stationary equipment is used. However many athletes and trainers prefer to monitor performance in real time under actual conditions. In rowing, some products measure rowing stroke cadence, power output and energy expended by direct or indirect measurements of the forces that the rower is applying to drive a vessel forward. Examples include mechanical strain gauges installed in an oarlock to measure the applied forces and, when combined with a measurement of the vessel speed, calculates power and energy. Such equipment is complex to install and expensive. Additionally, the same apparatus and equipment that can determine the power provided by a human may also be applied to powered vessels, for example power boats and sail boats."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "The disclosure of the present invention describes a novel approach to the determination of the amount of power produced and energy expended by a person or persons in propelling a water-going vessel, for example by rowing, sculling, or paddling or by a non-human power source such as an engine/propeller or sail. The term 'vessel' will be used throughout the instant disclosure, and refers to at least a rowing shell, paddle boat, dragon boat, row boat, canoe, kayak, power boat, sail boat and other human-powered and non-human powered water craft. The present invention determines the forces that oppose the motion of the vessel, any forces that aid in the motion of the vessel (such as a tail wind or water current), and determines the net resistive forces which must be overcome by the rowing motion. According to Newton's Third Law, the sum of these forces is equal and opposite to the force applied by the rower. These opposing forces comprise water skin drag, aerodynamic drag, and inertia.

"To determine the various forces which oppose movement of the vessel, the present invention provides a suite of sensors for obtaining data, the sensors mounted within a case on a vessel, facing the direction of motion. An accelerometer provides data related to changes in velocity. One or more differential pressure sensors provide data on the aerodynamic pressure applied against the front, back, or sides of the vessel and its occupants, thereby to calculate the net opposing or aiding aerodynamic force. Barometric pressure and air temperature values are used to estimate air density. Due to the relatively slow speed of a vessel, and given that wind may sometimes push forward from the rear of the vessel rather than pushing back from the front, some embodiments include a second set of sensors facing directly away from the first set of sensors.

"A sensor for measuring the velocity of the vessel through the water provides a value for calculating the drag due to water skin resistance, water form resistance, and other sources of energy loss in water such as wake formation that are functions of speed relative to the water surface. One example of a device for measuring vessel speed through the water is a hull-mounted impeller, for example an impeller available from Nielson-Kellerman, 21 Creek Circle, Boothwyn, Pa., 19061. Sensors based upon other technologies may be used, for example Doppler radar, digital imaging, sonar, and GPS.

"In some embodiments the calculations to derive forces from acceleration and wind pressure information are improved by input from the user or through calibration procedures. For example, the acceleration data is combined with the known or assumed total weight of the vessel and occupants to determine the force due to acceleration (vessel+occupant acceleration). Aerodynamic forces are calculated from aerodynamic pressure measurements combined with aerodynamic drag and area terms, which in some embodiments are improved by measurements from a coast-down procedure. Drag forces may be estimated, assumed, entered by a user, or measured by a coast-down calibration or other calibration procedures.

"Since water skin drag and aerodynamic drag act on the vessel simultaneously, in some embodiments the magnitude of the two factors is determined using a calibration procedure denominated a 'blow back procedure'. In this procedure, the vessel and occupants are allowed to be blown backwards by the wind until they reach a steady-state velocity relative to the water. By measuring the water speed and air speed, together with a previous measurement or estimate of the vessel's water skin drag as determined by a coast down procedure, the aerodynamic drag coefficient can be calculated. After completion of the blow back calibration, another coast down calibration is performed, using the measured value of aerodynamic drag, thereby to determine a refined value of water skin drag. With this refined value of water skin drag, another blow back calibration is performed, iteratively, until the values of water skin drag and aerodynamic drag stabilize. The coast-down procedure can then be done again with the refined value of aerodynamic drag iteratively improving the measurements of the drag coefficients with each additional calibration cycle.

"In other embodiments, the coast-downs are performed both into a head wind and then with a tail wind providing data that again can separate the action of the aerodynamic resistance from the water skin resistance. Using this method, both the skin drag coefficient and the aerodynamic drag coefficient are calculated simultaneously by fitting the combined data to the appropriately reduced equation of motion. Since the fitting is done on data where (1) water drag and air drag both slow the vessel and (2) wind aids the vessel motion and only water drag slows it down, the method provides an improved method for accurately calculating the water skin drag coefficient and the aerodynamic drag coefficient and separating the contribution of each to the resistance of vessel motion.

"In another embodiment, a vessel whose drag coefficient is to be measured is attached to another vessel and is towed through the water at a steady rate typical of the subject vessel. A strain gauge or other force measuring device is used to determine the total force required to pull the subject vessel forward at the desired speed. Once this force is determined it is a straightforward process to calculate the hull drag of the target vessel.

"In one embodiment these procedures are used in the same manner to determine the various parameters regarding a power boat, thereby enabling the same apparatus and methods to be used in determining the power delivered by the engine without monitoring the engine itself. Similarly, applying the same apparatus and methods to a sail boat determines the power provided by the sail to the boat.

"The sensors described by the instant disclosure are used by a microcomputer, which in turn calculates certain performance and status information. The results are presented to the user, and/or may be recorded for later analysis.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a top level schematic, indicating the connections between major functional blocks of one embodiment of the invention.

"FIG. 2 is a schematic showing connections to a microcontroller in the present invention.

"FIG. 3 is a schematic of a module which provides signals related to acceleration of a vessel.

"FIG. 4 is a schematic of a circuit providing bias voltages for a liquid crystal display device.

"FIG. 5 is a schematic of an interface to a liquid crystal display device.

"FIG. 6 is a schematic of a module which provides signals related to absolute pressure.

"FIG. 7 is a schematic of a module which provides signals related to differential pressure.

"FIG. 8 is a schematic of a battery supply to the system of the invention.

"FIG. 9 is a schematic of connections to a microcontroller in another embodiment of the invention.

"FIG. 10 is a schematic of a module which provides signals related to acceleration of a vessel.

"FIG. 11 is a top level schematic, indicating the connections between major functional blocks of one embodiment of the invention.

"FIG. 12 is a schematic of a module which provides signals related to absolute pressure.

"FIG. 13 is a schematic of a module which provides signals related to differential pressure.

"FIG. 14 is a schematic of a module which amplifies and filters differential signals.

"FIG. 15 is a schematic of a JTAG interface to an MCU.

"FIG. 16 is a schematic of a nonvolatile storage system.

"FIG. 17 is a schematic of a serial communications interface to an MCU.

"FIG. 18 is a top level flow chart of a method according to the present invention.

"FIG. 19 is a top level flow chart of a calibration procedure."

For additional information on this patent application, see: PAPE, TRAVIS; HAMANN, JOHN. Apparatus to Measure the Power Expended in Propelling a Vessel on Water. Filed April 26, 2014 and posted August 28, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=7124&p=143&f=G&l=50&d=PG01&S1=20140821.PD.&OS=PD/20140821&RS=PD/20140821

Keywords for this news article include: Electronics, Microcontroller, Velocomp, Velocomp Llc.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Electronics Newsweekly


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters