MEASUREMENT

Cross Reference to Related Application

[0001 ] This application claims the benefit of U.S. Provisional Patent

Application Ser. No. 61/949,297, filed on March 7, 2014, hereby incorporated by reference in its entirety.

Background of the Invention

[0002 ] Embodiments of the technology relate, in general, to the field of fluid flow measurement technology, and in particular to a device that non-invasively measures fluid flow in a conduit using vibration.

[0003 ] There are many devices used to measure the flow of fluids through a system such as a pipe. Examples of such devices are disclosed in U.S. Patent Nos. 8,347,427 and 8,887,324, each of which patent is hereby incorporated by reference in its entirety. These devices tend to have to be installed 'in-line' with the pipe. This means removing a section of the pipe or having to physically insert/replace a section of pipe with the device. This is a difficult installation procedure that typically requires a skilled technician to complete. With the rising costs of water it is becoming more important to monitor and adjust water use. Ease of installation and noninvasiveness has become highly desirable to this end. As such, there is a need for a fluid flow measurement device that could be installed without having to change the original system to be measured. This invention seeks to provide a solution that is easy to install and noninvasive while providing an accurate and real time

measurement of the fluid flow through the conduit.

Summary of the Invention

[0004 ] In various embodiments, this invention includes a device capable of sensing the flow of fluid in a system. The device can be affixed to the outside of the system directly. It does not require invasive installation (i.e. no changes to the system have to be made). This makes the invention particularly suited for a retro-fit or other application in existing systems. [0005 ] The invention in various embodiments includes of a sensor capable of detecting vibrations and a microprocessor capable of processing the information collected from the sensor. The device can be capable of transmitting the information over a wireless or wired connection via radio to a collector station or otherwise. It can be powered by various means such as a battery pack, main facility power, and or solar power.

[0006 ] The on-board microprocessor may use a series of algorithms to translate vibrational data to flow data. The algorithms can be tuned to improve the accuracy of the system.

[0007 ] The invention also extends to a method of gathering and/or processing fluid flow data.

Brief Description of the Drawings

[0008 ] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0009 ] Fig. 1 is a perspective view of one embodiment of this invention;

[0010 ] Fig. 2 depicts an example of an exploded perspective view of the embodiment of Fig. 1;

[0011 ] Fig. 3 depicts a more detailed view of a processor board used in the embodiments shown in Figs. 1 and 2;

[0012 ] Fig. 4 depicts elements of a system processor board according to one embodiment;

[0013 ] Fig. 5 depicts an algorithmic flow of the processor of Fig. 4

demonstrating how the data can be analyzed according to one embodiment of this invention; and

[0014 ] Fig. 6 depicts an example embodiment of the data analysis stage of the processing according to one embodiment of this invention. Detailed Description of the Invention

[0015 ] Various non-limiting embodiments of the this invention will now be described to provide an overall understanding of the principles of the structure, function, and use of the apparatuses, systems, methods, and processes disclosed herein. One or more examples of these non-limiting embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that systems and methods specifically described herein and illustrated in the

accompanying drawings are non-limiting embodiments. The features illustrated or described in connection with the non-limiting embodiment may be combined with the features of other non-limiting embodiments. Such modifications and variations are intended to be included within the scope of this invention.

[0016 ] Reference throughout the specification to "various embodiments," "some embodiments," "one embodiment," "some example embodiments," "one example embodiment," or "an embodiment" means that a particular feature, structure, or characteristic described in connection with any embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," "some example embodiments," "one example embodiment, or "in an embodiment" in places throughout the specification are not necessarily all referring to the same

embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0017 ] The invention can be used in a wide variety of fluid flow systems. The reader should be aware that where "pipe," "conduit" or similar terms are used, this can be interchanged with any fluid flow system.

[0018 ] Described herein are example embodiments of apparatuses, systems, and methods for noninvasively measuring fluid flow. In one example embodiment, a device of this invention uses a vibrational sensor to measure turbulent flow through a pipe, conduit or other structure. In some embodiments, the device is accompanied with a temperature sensor to measure convection flow through a system. In some embodiments, the device is capable of transmitting any data through a wireless or wired connection. In one embodiment the device uses a microprocessor to analyze the data from the vibrational sensor. In this embodiment, the processor uses a frequency domain transfer function to analyze the data stream. In various embodiments, an algorithm such as a Fourier transform or Laplace transform is used to analyze the resultant data.

[0019 ] The examples discussed herein are examples only and are provided to assist in the explanation of the apparatuses, devices, systems and methods described herein. None of the features or components shown in the drawings or discussed herein should be taken as mandatory for any specific implementation of any of these the apparatuses, devices, systems or methods unless specifically designated as mandatory. For ease of reading and clarity, certain components, modules, or methods may be described solely in connection with a specific figure. Any failure to specifically describe a combination or sub-combination of components should not be understood as an indication that any combination or sub-combination is not possible. Also, for any methods described, regardless of whether the method is described in conjunction with a flow diagram, it should be understood that unless otherwise specified or required by context, any explicit or implicit ordering of steps performed in the execution of a method does not imply that those steps must be performed in the order presented, but instead may be performed in a different order or in parallel.

[0020 ] Example embodiments described herein can appropriately determine the flow of fluid through a pipe in unit volume per unit time measurements as well as velocity measurements. For example, this invention may be used to measure the usage of water in a home. Additionally, or alternatively, industrial fluid systems can also be monitored.

[0021 ] Referring now to Fig. 1, the device 10 includes a vibration sensor to measure the minute deformations of a piping system having a fluid flowing there through. These vibrations can be analyzed using an on board micro processing system to determine the velocity of the fluid in the system. To determine the cross- section area of the pipe, a different sensor is used that can be wrapped around the pipe to determine its circumference. These two variables can be used to determine flow rate of the fluid in the pipe in unit volume per unit time.

[0022 ] The device 10 includes a main casing 12 which is used to hold the different components of the device 10. The casing 12 can be made out of plastic such as ABS, Nylon, PLA, or HDPE. It can be mounted onto a pipe, conduit or other system 14 in which fluid is flowing to be measured using a mounting arrangement which in one embodiment includes one or more the straps 16 that connect to mounting points 18. The straps 16 can be Velcro ^™ or any other type of material that would hold the device 10 to the pipe 14. The mounting arrangement may be of another design which temporarily or permanently mounts the device 10 to the pipe 14 in a removable or other fashion. The mounting arrangement may be a mechanical structure or a magnetic mount if the pipe 14 is at least partially ferrous in

composition. The pipe 14 in one embodiment has a circular cross-section with an outer peripheral dimension or circumference.

[0023 ] The mounting arrangement may position a sensor plate 20 against the system 14 in which fluid parameters are to be measured. The straps 16 are affixed to the case and wrap around the pipe 14. The straps 16 are then attached to the strap mounting points 18 to hold the casing 12 against the pipe 14. The pipe 14 may be a water supply pipe for a commercial or industrial building, apartment complex, individual residence, or other facility. The device 10 may be mounted to a cold or hot water supply pipe or a pipe carrying used water from the building to the sewer. The device 10 may be utilized for measuring the flow of other fluids also. These are but a few non-exhaustive examples of how and where the device 10 may be utilized within the scope of the invention.

[0024 ] The sensor plate 20 may be a plastic plate to which sensors within the device 10 can be attached to. Sensors 22 are mounted within the casing 12 and on the sensor plate 20 to provide intimate and constant contact with the pipe or system 14. Various embodiments of this invention use a vibration sensor 22 coupled to this sensor plate 20 to detect fluid flow in the pipe 14.

[0025 ] The vibration sensor 22 can be any sensor capable of measuring mechanical vibrations. This can be an electret microphone, an accelerometer, or any other sensor capable of measuring mechanical vibrations. One example sensor that can be used is an electret microphone part no. CEM-C9745JAD462P2.54R available from Challenge Electronics, www.challengeelectronics.com. The vibration sensor 22 should be capable of detecting vibrations of several thousand Hertz. Microphones are suitable for this type of use. Another possible sensor 22 is an accelerometer such as the ADXL335 available from Spark Fun, www.sparkfun.com. This sensor 22 is capable of measuring the vibrations in a pipe 14. Also, an ultrasonic transducer sensor 22 such as the 255-328SR16M-ROX available from Mouser Electronics, www.mouser. com, can be used to capture high frequency vibrations more effectively. The sensors 22 must be capable of measuring minute vibrations of fluid flow through the pipe 14.

[0026 ] For some embodiments, the device 10 can additionally use other sensors 22 to measure parameters of the pipe 14 and/or fluid within the pipe 14 other than vibrations. For example, a temperature sensor may be used to aid in fluid flow measurement. The temperature sensor may be capable of mitigating the high frequency noise of the vibration sensor 22. The vibration sensor 22 can also help mitigate issues with dead reckoning on the temperature sensor. The use of the temperature sensor benefits from the principle that as a fluid flows through a system 14, it carries away some of the heat at a rate proportional to its flow speed.

[0027 ] In some embodiments, the device 10 can be used in industrial applications to track the flow of caustic fluids or even gasses through a system 14. The device 10 can also be used in utility lines to monitor the flow of city water. The device 10 can be powered by a power source 24 such as a battery, mains voltage, general purpose alternating current (AC) elective power supply, solar energy, or any other suitable means. This allows the device to be used in a variety of different applications. A radio system may be included with the device to network itself with an array of device systems to better propagate the information being collected.

[0028 ] Fig. 2 depicts a more detailed exploded view of one embodiment of the device 10. A top plate 26 is affixed to the top of the casing 12. An antenna 28 goes through the top plate. An example antenna is the ANT-868-PW-LP-ND available at www.digikey.com. This was chosen because it is a sub-GHz antenna. Sub-GHz communication may be used because it passes through solid objects more effectively than higher frequency modes of transmission such as the common 2.4GHz. This may allow the device 10 to be used indoors and to pass data through walls to reach any sort of receiver.

[0029 ] In some embodiments, the straps 16 have an embedded sensor capable of measuring the cross-sectional area of the pipe 14 to be measured. In one example embodiment, a flex sensor is embedded in the strap 16 that can determine the appropriate bend of the pipe 14 and therefore its diameter which gives cross- sectional area. [0030 ] A bottom plate 30 is affixed to the bottom of the casing 12. Guide posts 32 are attached to the casing 12 allowing the sensor plate 20 to move freely. These posts 32 allow the sensor plate 20 to remain in contact with the pipe 14. A spring 34 is guided by a spring guide post 36 and pushes the sensor plate 20 against the pipe 14 as the device 10 is attached via the straps 18 to ensure contact. An example spring has an OD of 0.313" or big enough to fit over the spring guide post 36. It has a coefficient of force equal to 0.55 lbs/inch. This gives enough pressure to ensure good contact between the sensor plate 20 and the pipe 14 without risking damage to the sensors 22. The bottom plate 30 and/or the sensor plate 20 confronting the pipe, conduit or system 14 may be shaped to conform to the exterior shape of the pipe, conduit or system 14 for enhanced sensor detection capabilities as the installation requirements may indicate.

[0031 ] A battery compartment 38 in the device 10 holds the power source 24 that powers a processor 40. An example power source 24 is a set of four AA batteries. These batteries can then be regulated by a buck regulator such as the MCP1252 available at www. mouser.com or the sake of power efficiency or an LDO regulator such as the TC1262-3.3VDBCT-ND available at

www, avnetexpress.avnet. com for ease of setup and low cost.

[0032 ] Fig. 3 depicts an example embodiment of a processor board 40 and how it might be affixed to the device 10. The antenna 28 is electrically connected to the processor board 40. In this example embodiment, the processor board is affixed to the top plate 26.

[0033 ] Fig. 4 depicts an example embodiment of the processor board 40 and its systems. The processor board 40 may be a PCB that is custom designed for the system. It may be less than 2.5" by 1.5" to ensure a small footprint and to minimize material costs. The main processing unit is a micro controller 42 capable of reading, parsing, and transmitting the collected data. An example is the CC1111F32. A radio 44 produced by Texas Instruments is low cost, low power, and has an on board 8051 processor. This keeps the overall cost low by minimizing part count. The processor is capable of an on board ADC to measure the sensors and can do the flow

computations on board the system 14. The radio 44 communicates with the micro controller 42 to transmit the necessary information. The radio 44 may be its own distinct unit or part of the microcontroller 42 itself. An usb connection 46 allows for firmware updates in the case that there is a flaw or vulnerability in the release version. Display LEDs 48 show the user that the device 10 is in fact powered and to present possible diagnostics in case the device 10 has issues. The power source 24 can take several forms. This may be standard batteries that are regulated to power the device 20. It can also be a wired system, a solar system, or some other type of external power. The pre-processing and filtering stage 50 converts the output of the vibration sensor 22 into one or more formats usable by the microprocessor 40. This could mean amplification stages, filter stages, or data form conversion stages.

[0034 ] Fig. 5 depicts an example embodiment of the software flow of the processor 40. The processor operational flow begins at start 52 and moves to the wait stage 54 where it cycles until it is ready to take measurements or collect data 56. In some embodiments this could be an interrupt timer that wakes the processor from a sleep cycle to process the data. Once the device is ready to collect the data 56 it does so. This could be through an internal analog to digital converter or a digital communication line. If it is through a digital communication line, an external converter will be used. The processor then runs the data through a frequency processing stage 58. This takes the time domain data and converts it to frequency domain. In some embodiments this is done through the use of a fast fourier transform (FFT) algorithm such as the Cooley-Tukey algorithm. An example implementation of the Cooley-Tukey algorithm is as follows:

double PI;

typedef double complex cplx;

void_fft(cplx buf[], cplx out[], int n , int step)

{

if (step < n) {

- fft(out, buf, n, step * 2);

- fft(out + step, buf + step, n, step * 2);

for (int i = o; i < n; i += 2 * step) {

cplx t = cexpq(-I * PI * i / n) * out[i + step];

buf[i / 2] = out[i] + 1;

buf[(i + n)/2] = out[i] - t;

}

}

}

void fft(cplx buf[], int n)

} cplx out[n];

for (int i = o; i < n; i++) out[i] = buf[i];

_fft(buf, out, n, 1);

}

int main ()

{

PI = atan2(1, 1) * 4;

cplx buf [32];

getDataPoints (buf) ;

fft(buf, 8);

return O;

}

[0035 ] In this example buf is loaded with the data points read from the sensors using the function getDataPoints. Then buf is passed through the FFT function that converts the elements in buf to the frequencies present in buf. This takes the form of an array of discrete frequencies and their relative magnitudes. The processor then converts the frequency spectrum to a flow rate 60. In one example embodiment this is done by using a weighted linear regression system that maps frequencies to flow rates. This is a function of the form A + BXi + CX ₂ +... ZX _n where n is the length of the list (i.e. number of frequencies) and Z is an arbitrary coefficient. Each element X is a different frequency that has been calculated. This function then converts frequency to flow rate. The data is then transmitted 62 over the radio 44 to a remote receiving station. In some embodiments this may be a proprietary radio. In other embodiments this may be WFi transmission. The station may be any device capable of capturing and displaying this data. In some embodiments this might be an LCD enabled device that can show usage over time.

[0036 ] Fig. 6 depicts an example embodiment of the data analysis stage of the processing. The processor begins with data preparation 64. This stage can help clean up the data in preparation for analysis. This means removing known extraneous noise to improve the analysis. In the next stage the data is passed through a domain transfer function 66. In one example embodiment this is a Fourier Transform algorithm. This may use a Cooley-Tukey Fast Fourier Transform to convert the data to frequency domain. Some example embodiments may convert the data to a series of moment modes using a Laplace Transform. The conversion stage 68 is next and takes the resultant data and changes it to flow rate values. Some embodiments will use a linear model to convert frequencies to flow rates. This can be calculated using multiple linear regressions. The unification stage 70 brings the multiple elements of data together to form a unit volume per unit time measurement.

Some embodiments might make use of a temperature sensor 22 to smooth out high frequency noise from the vibration sensor model. One example embodiment would use an Unscented Kalman Filter Algorithm to unify the temperature data and the vibration data into a single flow measurement. The Unscented Kalman Filter is similar to the linear regression algorithm. However, it adds non-linear elements to the function to see how different inputs correlate. If this algorithm proves too advanced in terms of processing power and development, an alternative is to use a simple step correlation function where the two sensor data elements are combined by averaging the current state of the vibration sensor with the trend of the temperature sensor to yield a unified measurement. Example code for this is as follows:

int unify(int temp, int vib)

{

static int tempPrev;

int newFlow = vib*vibGain + (currentFlow + (temp - tempPrev))*tempGain; tempPrev = temp;

return newflow;

}

[0037 ] Where temp and vib are the flows as calculated by the temperature and vibrational sensor respectively. newFlow is calculated by taking the current vib measurement and adding it to the current flow measurement plus the change in the rate measured by the temperature sensor. The vibGain and tempGain create a weighted average of the two elements of the measurements. This information is then paired with the cross-sectional area of the system to provide unit volume per unit time measurements. The result is then passed to the formatting stage 72 which makes the necessary conversions on the data to a point that is suitable for transfer.

[0038 ] In general, it will be apparent to one of ordinary skill in the art that at least some of the embodiments described herein can be implemented in many different embodiments of software, firmware, and/or hardware. The software and firmware code can be executed by a processor or any other similar computing device. The software code or specialized control hardware that can be used to implement embodiments is not limiting. For example, embodiments described herein can be implemented in computer software using any suitable computer software language type, using, for example, conventional or object-oriented techniques. Such software can be stored on any type of suitable computer-readable medium or media, such as, for example, a magnetic or optical storage medium. The operation and behavior of the embodiments can be described without specific reference to specific software code or specialized hardware components. The absence of such specific references is feasible, because it is clearly understood that artisans of ordinary skill would be able to design software and control hardware to implement the embodiments based on the present description with no more than reasonable effort and without undue experimentation.

[0039 ] Moreover, the processes described herein can be executed by programmable equipment, such as computers or computer systems and/or processors. Software that can cause programmable equipment to execute processes can be stored in any storage device, such as, for example, a computer system

(nonvolatile) memory, an optical disk, magnetic tape, or magnetic disk.

Furthermore, at least some of the processes can be programmed when the computer system is manufactured or stored on various types of computer-readable media.

[0040 ] It can also be appreciated that certain portions of the processes described herein can be performed using instructions stored on a computer-readable medium or media that direct a computer system to perform the process steps. A computer-readable medium can include, for example, memory devices such as diskettes, compact discs (CDs), digital versatile discs (DVDs), optical disk drives, or hard disk drives. A computer-readable medium can also include memory storage that is physical, virtual, permanent, temporary, semipermanent, and/or

semitemporary.

[0041 ] A "computer," "computer system," "host," "server," or "processor" can be, for example and without limitation, a processor, microcomputer, minicomputer, server, mainframe, laptop, personal data assistant (PDA), wireless e-mail device, cellular phone, pager, processor, fax machine, scanner, or any other programmable device configured to transmit and/or receive data over a network. Computer systems and computer-based devices disclosed herein can include memory for storing certain software modules used in obtaining, processing, and communicating information. It can be appreciated that such memory can be internal or external with respect to operation of the disclosed embodiments. The memory can also include any means for storing software, including a hard disk, an optical disk, floppy disk, ROM (read only memory), RAM (random access memory), PROM (programmable ROM), EEPROM (electrically erasable PROM) and/or other computer-readable media. Non-transitory computer-readable media, as used herein, comprises all computer- readable media except for atransitory, propagating signals.

[0042 ] In various embodiments disclosed herein, a single component can be replaced by multiple components and multiple components can be replaced by a single component to perform a given function or functions. Except where such substitution would not be operative, such substitution is within the intended scope of the embodiments. Some of the figures can include a flow diagram. Although such figures can include a particular logic flow, it can be appreciated that the logic flow merely provides an exemplary implementation of the general functionality. Further, the logic flow does not necessarily have to be executed in the order presented unless otherwise indicated. In addition, the logic flow can be implemented by a hardware element, a software element executed by a computer, a firmware element embedded in hardware, or any combination thereof.

[0043 ] The foregoing description of embodiments and examples has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed, and others will be understood by those skilled in the art. The embodiments were chosen and described in order to best illustrate principles of various embodiments as are suited to particular uses contemplated. The scope is, of course, not limited to the examples set forth herein, but can be employed in any number of applications and equivalent devices by those of ordinary skill in the art. Rather it is hereby intended the scope of the invention to be defined by the claims appended hereto.

[0044 ] From the above disclosure of the general principles of this invention and the preceding detailed description of at least one embodiment, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, I desire to be limited only by the scope of the following claims and equivalents thereof.

[0045 ] We claim: