CROSS REFERENCE

[0001] This application claims benefit of U.S. Provisional Patent Application No. 62/134,539, filed March 17, 2015 and U.S. Provisional Patent Application No. 62/262,227, filed December 2, 2015, the specification(s) of which is/are incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to improvements to pool water systems, more specifically the present invention relates to regulation of pool water cleaning systems and occupancy of pools.

BACKGROUND OF THE INVENTION

[0003] It is well known that in a swimming pool, it is necessary to keep water "clean" by maintaining a good water circulation level and using the correct levels of additives, i.e. feed or chemical products (e.g. chlorine, muriatic acid, or similar). The needed water flow and chemical quantity depend on various factors, but one of the most important that can vary easily is the number of persons inside the swimming pool (especially in large swimming pools or public swimming pools). There are systems that can measure the level of chemistry inside the water, such as indicating when more products are required if the level is not ideal, but the consumption of these products depends also to the water flow that is circulating inside the pool. The circulation is created by a specific pump system controlled by a dedicated device. In the simplest cases, the device is a timer, and for bigger pools and public pools, it could be a programmable logic controller (PLC).

[0004] Normally, the circulation is set without considering the number of persons that are inside the pool. The circulation can be set by systems that switch on and off the pumps within a specific period of time, for example, "n" minutes on and "m" minutes off (where "n" and "m" are variable numbers). This configuration could work in private small swimming pools, where the variation of crowd is not so important. Moreover, these pools cannot keep more than a few people and normally are not used extensively. In bigger pools, especially in public pools, the conditions are different. During the day, the crowd level of the pool can vary significantly. Because the most important requirement is to keep the water clean, in the previous and common configurations, the pumps would run even when nobody is inside the pool; the consequence is waste of energy (using the pumps) and additives (due to unnecessary water flow).

[0005] There are other systems that can control the number of access to the pool area, for example, using turnstiles and toll gates at the entrance of the building. In these cases, the pumps speed and the chemistry are regulated by a PLC basing on that number. Even if this is a "greener" configuration compared to the first one, these systems cannot know how many people are actually inside the pool. For instance, many of them could be just in the building or in the area around the pool but not inside the water, e.g. in a water park or similar locations. This limitation can be cause for waste of energy and additives.

[0006] The purpose of the device described herein is for monitoring the status of a swimming pool, understanding the level of crowding of the pool, and transmitting the data to the circulation controlling system of the pool to regulate, for example, the pump speed and additive concentration based on effective need.

SUMMARY OF THE INVENTION

[0007] The system described in this patent is constituted of a series of devices that create a kind of matrix for the specific swimming pool: from the interaction between those devices a central control unit can understand the status of the various "cells" constituting the pool area and, more in general, the crowd level of the swimming pool at that moment.

[0008] The core technology of the each device is the analysis of the output signal as measured by the receiving transducer. This signal contains the echoes of ultrasonic waves generated by appropriated ultrasonic transducers inside the swimming pool; the same transducers can work as transmitter and receiver. The signal is processed by a front end electronics and the output is analyzed by a digital processing unit. [0009] According to one embodiment, the present invention features an ultrasonic pool occupant sensing device, capable of using ultrasonic pulses to analyze an occupancy level of a pool. The device may comprise an ultrasonic transducer, capable of sending and receiving ultrasonic pulses, wherein the transducer emits an ultrasonic pulse when activated by an electronic pulse, wherein the transducer generates an electronic signal when it receives an ultrasonic pulse; a front end electronics system operatively connected to the ultrasonic transducer capable of processing incoming and outgoing electronic signals from the transducer; and a digital processing system.

[0010] In some embodiments, the front end electronics system may comprise a driver capable of sending an electronic pulse to the transducer; a low-noise pre-amplifier, capable of receiving an electronic signal from the transducer; a band-pass filter, operatively connected to the pre-amplifier, capable of filtering the electronic signal from the transducer; and an amplifier, operatively connected to the band-pass filter, capable of amplifying the electronic signal receiver from the band-pass filter.

[0011] In other embodiments, the digital processing system may comprise a timer unit, configured to signal the driver to generate the electronic pulse at intervals; an input/output unit, capable of sending and receiving data to and from the front-end electronics system and the processing system; an analog to digital converter, configured to convert the electronic signal received from the transducer from analog to digital; and a signal processor, configured to analyze the electronic signal and produce data concerning a number of occupants in the range of the transducer.

[0012] In one embodiment, the pool occupant sensing device is placed inside the pool. The timer unit of the digital processing unit sends a timing signal to the driver of the front end electronics, whereupon the driver generates an electronic pulse. The pulse is then transmitted to the ultrasonic transducer. The ultrasonic transducer emits an ultrasonic pulse which is transmitted into the pool at intervals, for example, regular or irregular intervals etc. The ultrasonic pulse is reflected off of the walls and occupants within the pool. The transducer receives a signal that depends also on the echoes due to the various occupants and walls of the pool. The transducer generates a received electronic signal, which is passed through the pre-amplifier, band-pass filter, and amplifier of the front end electronics. The received signal is acquired by the analog-to-digital converter of the digital processing unit, which passes the digital signal to the signal processor. The signal processor generates data concerning the number of occupants in the pool, and the input/output unit permits the data to be transmitted to the central unit or to an external processor.

[0013] In another embodiment, the signal processor compares data derived from the ultrasonic pulse transmitted into the pool at intervals, for example regular or irregular intervals etc, to determine a change in the occupancy level. In a further embodiment, the external processor is operatively connected to a visual display unit to display the aggregate estimate of the total number of occupants and/or the position of occupants in the pool.

[0014] According to another embodiment, the present invention features a pool occupancy level system comprising at least one of the ultrasonic pool occupant sensing devices described herein. The external processor can collect data from each pool occupant sensing device, and generate an aggregate estimate of the total number of occupants in the pool. For example, the system may comprise a plurality of pool occupant sensing devices, wherein the pool occupant sensing devices communicate data and commands between them exploiting ultrasound waves travelling into water

[0015] In still other embodiments, the present invention may feature a pool-water regulation system, based on sonar detection of a number of occupants in a pool. The system may comprise a central processing unit, at least one ultrasonic pool occupant sensing device described herein, operatively connected to the central processing unit and disposed inside a pool, and a pool water circulation control system, capable of adjusting the rate at which water is pumped through the pool and the amount of additives added, operatively connected to the central processing unit.

[0016] The central processing unit can collect data from each ultrasonic pool occupant sensing device, and generate an aggregate estimate of the total number of occupants in the pool. The central processing unit controls the pool water circulation system to adjust the additive dispensation and pump rate of the circulation system according to the number of occupants in the pool. In some embodiments, the pool occupant sensing devices are arranged to form a grid across the pool. The central processing unit can determine how many occupants are in each section of the grid, and the pool circulation in each grid section is independently controlled. In other embodiments, the pool occupant sensing devices communicate data and commands between them by exploiting ultrasound waves travelling into water. In one embodiment, the additives comprise cleaning chemicals or solutions. In another embodiment, the additives comprise feed.

[0017] In further embodiment, the present invention may feature an ultrasonic pool occupant sensing device, capable of using ultrasonic pulses to analyze an intrusion in a pool. The device may comprise an ultrasonic transducer capable of sending and receiving ultrasonic pulses, a front end electronics system operatively connected to the ultrasonic transducer, and a digital processing system. The ultrasonic transducer can emit an ultrasonic pulse when activated by an electronic pulse, and can generate an electronic signal when it receives an ultrasonic pulse.

[0018] In one embodiment of the present invention, the front end electronics system may comprise a driver capable of sending an electronic pulse to a transducer, a low- noise pre-amplifier, capable of receiving an electronic signal from the transducer, a band-pass filter, operatively connected to a pre-amplifier, capable of filtering the electronic signal from the transducer, and an amplifier, operatively connected to the band-pass filter, capable of amplifying the electronic signal receiver from the bandpass filter.

[0019] In another embodiment of the present invention, there is provided a digital processing system comprising a timer unit, configured to command a driver to generate an electronic pulse, an input/output unit, capable of sending and receiving data to and from the front-end electronics system and the processing system, an analog to digital converter, configured to convert the electronic signal received from the transducer from analog to digital, and a signal processor, configured to analyze the received digital signal and produce data concerning a number of occupants in the range of the transducer. [0020] The pool occupant sensing device may be placed inside the pool, and the timer unit of the digital processing unit sends a timing signal to the driver of the front end electronics at intervals, for example, regular or irregular intervals etc. The driver generates an electronic pulse, which is transmitted to the ultrasonic transducer. The ultrasonic transducer emits an ultrasonic pulse which is transmitted into the pool.

[0021] In one embodiment, the ultrasonic pulse is reflected off the walls and an intrusion within the pool. The transducer receives a signal that depends also on the echoes due to the intrusion and walls of the pool. The transducer generates a received electronic signal, which is passed through the pre-amplifier, band-pass filter, and amplifier in the front end electronics. The received signal is transmitted to the digital processing unit that passes the signal through the analog-to-digital converter to produce a digital signal of the pulse. The signal processor generates data concerning the presence of the intrusion in the pool, and the input/output unit permits the data to be transmitted to an alarm system.

[0022] In some embodiments, the signal processor compares data derived from the ultrasonic pulse transmitted into the pool at intervals, for example, regular or irregular intervals etc. to determine an intrusion in the pool. The data can be transmitted to a visual display unit to display the aggregate estimate the position of the intrusion in the pool. In other embodiments, the alarm system is a remotely located alarm system. The data can be transmitted to the remotely located alarm system wirelessly.

[0023] According to further embodiments, the present invention features a pool intrusion system comprising one or more of the ultrasonic pool occupant sensing devices described herein. In one embodiment, the pool occupant sensing devices can communicate data and commands between them wirelessly. In another embodiment, the pool occupant sensing devices communicate data and commands between them exploiting ultrasound waves travelling into water.

[0024] Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows an exemplary schematic diagram of the ultrasonic sensing device of the invention.

[0026] FIG. 2 shows a possible example configuration of the system of the invention using five devices within a swimming pool.

[0027] FIG. 3 shows a second possible example configuration of the system of the invention using three devices within a swimming pool.

[0028] FIG. 4 shows an example process flow for the system of the present invention.

[0029] FIG. 5 shows a schematic diagram of the ultrasonic sensing device according to a second embodiment of the invention.

[0030] FIG. 6 shows an example of a return signal from the ultrasonic transducer mounted in an empty pool.

[0031] FIG. 7 shows an example of a return signal from the ultrasonic transducer mounted in the same pool with a person in the middle.

[0032] FIG. 8 shows a schematic plan view of a small pool with a person.

[0033] FIG. 9 shows a schematic plan view of a large pool with a person.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] In the following description, functionally similar parts carry the same reference numerals between different embodiments. The drawings are intended to be schematic, and dimensions, scale and/or angles may not be determined accurately from them unless otherwise stated.

[0035] Within the statement of invention, description and claims, unless otherwise stated, the terms occupants, people and objects are intended to have equivalent meaning, i.e. bodies, foreign bodies or contaminants that are not permanent fittings, fixtures or structures of the pool, but it does not necessarily imply whether the occupants are static or dynamic objects. [0036] Within the statement of invention, description and claims, unless otherwise stated, the terms pool and swimming pool are intended to have equivalent meaning, i.e. an enclosure, chamber, vessel or storage container suitable for containing fluids or water, but it does not necessarily imply that the enclosure, chamber, vessel or storage container is exclusively for human use.

[0037] Within the statement of invention, description and claims, unless otherwise stated, the terms chemical products, solution, feed etc. are intended to have equivalent meaning, i.e. additives or supplementary products to be dosed into the pool.

[0038] Within the statement of invention, description and claims, unless otherwise stated, the terms signal(s), data, pulse(s) etc. are intended to have equivalent meaning, i.e. transmission of information.

[0039] Within the statement of invention, description and claims, unless otherwise stated, the term actual signal means live or real-time signal, i.e. the most recent or newly acquired signal with respect to time, but it does not necessarily imply that the signal is limited to a specific signal bandwidth/range, frequency range, background noise and/or interference.

[0040] Within the statement of invention, description and claims, unless otherwise stated, the terms water and liquid are intended to have equivalent meaning, i.e. a body of fluid.

[0041] Within the statement of invention, description and claims, unless otherwise stated, the term interval includes regular, irregular and random intervals, but does not necessary imply that its frequency or cycle is a defined by an integer, value, formula or equation.

[0042] Within the statement of invention, description and claims, unless otherwise stated, the terms unit and system are intended to have equivalent meaning, i.e. an apparatus with an intended purpose, but it does not necessarily imply that the apparatus is a discrete device or an arrangement having a series of discrete devices. [0043] Referring now to FIG. 1 -4, in a first embodiment, the system of the present invention comprises a pool-water regulation system, based on ultrasonic frequencies (i.e. between 20 kHz to 300MHz) for detecting of the number of people in a swimming pool. Higher frequencies may be used in other applications to detect smaller objects such as krill. The system comprises a central processing unit, at least one ultrasonic pool occupant sensing device, operatively connected to the central processing unit, disposed inside a swimming pool, a pool water circulation control system, capable of adjusting the rate at which water is pumped through the pool and the amount of cleaning chemicals added, operatively connected to the central processing unit. The central processing unit collects data from each pool occupant sensing device and generates an aggregate estimate of the total number of occupants in the pool. The central processing unit then controls the pool water circulation system to adjust the chemical dispensation and/or flow rate of the circulation system according to the number of occupants in the pool.

[0044] In a typical embodiment, the ultrasonic pool occupant sensing device contains an ultrasonic transducer, capable of sending and receiving ultrasonic pulses. The transducer emits an ultrasonic pulse when it is driven by an electronic pulse, and generates an electronic signal that contains the echoes due to the ultrasonic waves.

[0045] The sensing device also contains a front end electronics unit, operatively connected to the ultrasonic transducer, comprising: a driver capable of sending said electronic signal to the transducer, a low-noise pre-amplifier, a band-pass filter, and an amplifier, which filter and amplify the electronic signal received from the bandpass filter. The sensing device further contains a digital processing unit comprising: a timer unit, configured to command the driver to generate an electronic pulse, an input/output unit, capable of sending and receiving signals to and from the front-end electronics unit and the central processing unit, an analog to digital converter, configured to digitize a signal received from the transducer, and a signal processor, configured to analyze a received signal and produce data concerning the number of people in the range of the transducer.

[0046] Each pool occupant sensing device is placed inside a swimming pool, wherein the timer unit of the digital processing unit sends a pulse to the driver of the front end electronics at intervals, for example regular or irregular intervals etc. The driver generates an electronic pulse, which is transmitted to the ultrasonic transducer, whereupon the ultrasonic transducer emits an ultrasonic pulse which is transmitted into the swimming pool. An echo is generated by the ultrasonic pulse reflecting off the walls of the swimming pool and off the occupants within the swimming pool. The transducer receives said echo, whereby the echo depends on different distances at which the echo has to travel when reflecting off the various occupants and walls of the pool. The receiving transducer generates an electronic signal derived from the echoes, and the received electronic signal is passed through the pre-amplifier, bandpass filter, and amplifier of the front end electronics to the analog-to-digital converter of the digital processing unit to produce a digital signal. The signal processor elaborates the digital signal keeping into consideration both the energy and morphology of the signal and the time of flight and generates data concerning the number of occupants in the pool. The input/output unit permits this data to be transmitted to the central processing unit.

[0047] As described before, the system is constituted by a series of devices, each of them works for a certain area of the swimming pool that could be just a part or the total, controlling it based on the received signals due to the ultrasonic waves and their analysis. Each device can communicate data and commands between them by exploiting the ultrasonic waves: they can use coded ultrasonic signal in order to synchronize operations of the overall system or to exchange data. Any object inside the volume of water (including walls and peoples) reflects (totally or partially) the ultrasonic waves (generated by the transducers) creating echoes; when these echoes come back to one of the transducers, change the output signal generated at the edges of it (because of the water pressure and the nature of piezoelectric material inside the transducer).

[0048] The acquisition of the voltage signals are obtained in the following way:

a. driving of a transmitter (the ultrasonic transducer of that device) through a pulsed signal to generate a train of ultrasonic waves in the water volume of the swimming pool; b. acquisition of the voltage signals measured by the ultrasonic waves arrived to the receiving transducer and coming from the rebound of ultrasonic waves on the walls and / or any possible objects and persons contained in the volume of water of the pool; those ultrasonic waves could be generated by the device itself and/or by another transducer / source of ultrasonic waves).

[0049] When those signals are acquired by the A/D converter, the digital processing unit analyzes them in various ways to extract the desired information about the status of the specific area of swimming pool controlled by that device; examples of the quantities that can be evaluated could be:

L time of flight of the different echoes due to the various objects / people: calculating the time between the generated waves and the various echoes peaks - with this data it could be possible estimate, for example, the distance between the transducer and the objects;

2. energy and its change of the signals measured by the transducer, wherein the transducer operates as a receiver; the energy of the measured signal changes, for example, due to the people inside the pool (because of the nature of living tissues and air presence inside the body) and any background signals;

3. comparison on morphology with respect to a "reference" echo signal: various algorithms to evaluate how much different the actual signals could be respect to the "reference" echo signal (that could be, for example, the echo signal of that area of swimming pool when the pool is empty or when it is considered at the maximum capacity of people).

[0050] When these data are collected, the control unit of each device sends a part of them (or all of them, depending on the application) to a central unit: this central unit communicates with all the devices and with the proper algorithm it can determinate the status of the various areas (or "cell" of the matrix) of the swimming pool; using this information, the central unit can send to the water circulation system of the swimming pool (that is considered external at the system described in this patent) the instructions to use water flow and chemistry based on effective need. [0051] The physical system comprises a central processing unit, one or more devices, each one with ultrasonic transducer(s), a front end electronics, and a digital processing unit. The central unit is responsible to manage, coordinate and communicate with all the devices; moreover, it communicates instruction to the external water circulation system of the swimming pool. The ultrasonic transducers are responsible for the generation and the detection of the ultrasonic waves. The front end electronics are responsible for the driving signal of the ultrasonic transmitter and the acquisition of the voltage signals coming from all the transducers working as a receiver. The digital processing unit contains the algorithm that implements the elaborating technique previously described. The communication between the various devices and the central unit, as well as the communication between central unit and the external systems could be with cable or wireless or by ultrasonic waves (any method / technology to communicate between devices could be used). The power supply for all the system could be done using any proper method (e.g. batteries, proper transformers connected with the local electrical power supply).

[0052] As shown in FIG. 1 , each sensing device (100) comprises an ultrasonic transducer (108), a front end electronics (102), and a digital processing unit (104). The ultrasonic transducer (108) sends and receives the signal caused by the ultrasonic waves. The front end electronics comprises a driver (103) for controlling the transducer, a pre- amplifier (109), band-pass filter (1 10), and amplifier (1 1 1 ) combination for filtering received signals. The digital processing unit contains a timer unit (105) for generating pulses, an AD converter (1 12) for digitizing received pulses, a signal processor (1 13) for determining data about the return pulse, and an I/O unit (106) for transmitting data to the central processing unit (107). The data may be an estimate of the number of people in the sensor range, or it may be data about the return pulse that can be analyzed by the central processing unit.

[0053] In some embodiments, the mode of operation of the transducer may be alternated between a "shooting time" and an "acquisition time", wherein the timer is configured to send a pulse during the shooting time, at which time the transducer is in a transmission mode. The transducer is then switched into a receiving mode for a length of time necessary to capture the echoes. In some embodiments, the control unit may be programmed with a stored "reference signal", which is recorded when the pool is empty. The reference signal is used for comparison to the return signal in estimating the number of people in the pool.

[0054] The "reference signal" can be updated or replaced with a new reference signal, for example, if there has been a physical or geometric change in the pool such as a newly installed structure or ladder, or the removal of an existing structure or ladder, and/or a variation in the physical and/or chemical characteristics of the water inside the pool, such as a change in the water temperature. This allows the sensing 100 device to have a more accurate comparison of data.

[0055] Advantageously, upon sending, receiving and converting data at intervals, for example regular or irregular intervals etc, concerning the number of occupants in the pool, the control unit can detect a change in occupancy level by comparing newly acquired signal (actual signal) against previous signal.

[0056] As shown in FIG. 2 the devices (201 ) may be arranged around the sides of the pool (200) so as to form a grid. In this way the central unit (202) can estimate the number of people in each section of the grid based on the shape of the return pulse, such as the timing of reflections indicating distance from the transducer. The estimate is then used to adjust the circulation control system (203).

[0057] As shown in FIG. 3 the devices (301 ) may be arranged on the bottom of the pool (300), with one device per section. In this way the devices may each generate an estimate of the number of people in each section. A central processing unit (302) then combines the estimates and uses the numbers to adjust the circulation control system (303).

[0058] FIG. 4 shows an example process flow for the system of the present invention. The timer unit generates pulses (601 ). The frequencies of the pulses are sized to permit the return pulse to echo from the far wall of the pool and be received by the transducer. The driver generates an electrical signal intended to drive the ultrasonic transducer (602). This signal is then sent to the ultrasonic transducer and causes the transducer to emit an ultrasonic pulse (603). The pulse echoes off the walls and people in the pool and is reflected back to the transducer. The transducer thus receives different echoes as return signal (604). The transducer is switched into the receiving function and generates an electronic signal of the return signal (605). This signal is then passed through a filter in the front-end electronics (606), and is converted to a digital form in the digital processing unit (607). The signal processor analyzes the return pulse and computes data about the pulse (608) which is then sent to the central processing unit (609). The central processing unit then estimates the aggregate number of occupants in the pool (610) and uses this estimate adjust the circulation control system (61 1 ) so as to optimize the dispensation of cleaning chemicals.

[0059] FIG. 5 shows a schematic diagram of the ultrasonic sensing device 700 that may be used to detect intrusion in the pool, for example, a child or animal falling into the pool. In this embodiment, the sensing device 700 contains identical components as the first embodiment of the ultrasonic sensing device 100, where the similar components will use the same reference numerals. As described above, the device 700 comprises an ultrasonic transducer (108), a front end electronics (102), and a digital processing unit (104). Unless otherwise stated, it is not intended to further describe the operation, features and function of the similar components to avoid duplication.

[0060] FIG. 6 shows an example of a return signal when nobody is in the pool. FIG. 7 shows for comparison an example of a return signal when there is an occupant in middle of the pool. The signal of FIG.7is a modification of the signal of FIG. 6 and indicates the presence of a person halfway across the pool.

[0061] In a second embodiment, the mode of operation of the transducer may be alternated between a "shooting time" and an "acquisition time", as described above where the transducer sends the pulse during the shooting time in the transmission mode. The transducer is then switched into the receiving mode for a length of time necessary to capture the return pulse. Referring again to FIG. 6 and 7, FIG.6 shows the signal captured by the control unit when no person is in the pool and the return signal is reflected off the pool wall, and the control unit stores this signal as the "reference signal". However, when a person enters the pool, the return signals would reflect off the person and walls of the pool, as shown in FIG.7. The device 700 analyzes the signals to determine a person intruding the pool, whereupon the device 700 will send a signal to an alarm system 701 to notify a person intruding the pool. The alarm system may be housed locally with the sensing device. Advantageously, the alarm system may be a remotely located alarm system, and in which case the device may be wirelessly connected to the remotely located alarm system.

[0062] The device 700 can be configured to learn the physical characteristics of individual pools, e.g. the geometry of the pool and presence of structures such as ladders etc., by the returned signal which will be stored as the reference signal. The timer unit 105 of the digital processing unit 104 sends a timing signal to the driver 103 of the front end electronics 102 at intervals regular or irregular to monitor the pool. By comparing the stored reference signal and the newly acquired signal, the control unit can detect intrusion in the pool.

[0063] As described above, the device 700 can differentiate a physical body intruding the pool from background signals such as rain drops penetrating the water surface by the returned signals. For example, when a person intrudes the pool, the waves are partially reflected (because of the nature of living tissues and air presence inside the body). Therefore, the variation in the energy of the returned signal during the flight time can be an important quantity to be evaluated.

[0064] In general, the voltage signals measured by the transducer coming from the rebound of ultrasonic waves can be dependent upon one or more of the following conditions:

a. geometry of the pool, for example, its dimensions, shape and structures such as ladder or ducts etc.;

b. geometry of the transducer(s), for example, its position and orientation etc.; c. temperature of the water;

d. underwater currents due to a recirculation system; and

e. environmental parameters such as wind, rain etc.

[0065] The above conditions can be varied between different pools, as each pool can have its own characteristic. However, one of the features of the present invention is the comparison of signal between the reference signal and newly acquired signal (actual signal), whereby a threshold value between the compared data can be used to determine intrusion in a pool. The threshold value can differentiate a person intruding the pool from background noise/data derived from change in water conditions, such as change in temperature or underwater currents.

[0066] Due to nature of ultrasonic waves, i.e. speed of sound in water is 1482 m/s, in larger pools more than one device 700 can be used. In FIG. 8 show a single device 700 fitted in a smaller pool 800 to detect the intruder 812. In FIG. 9shows multiple devices 700, 700a, 700b fitted in a larger pool 810 to detect the intruder 814. As shown in FIG. 9, the signal from the device 700 has to travel double the distance in comparison to the device 700 in FIG. 8. However, in a situation where potentially a child can fall in the pool, time is a critical. Therefore, in the larger pool 810 where the device 700b is closer to the intruder 814 can provide an earlier alert/warning.

APPLICATIONS

[0067] Although the embodiments disclose the use of the device or system for swimming pool applications, it can be envisaged that the device or system can be used in detecting anomalies or a collection of articles in a water enclosure such as a school of fish, a pool cleaning or feeding system applications for fisheries, chemical dosing systems for chemical baths, food or beverage industries, fluid and refining processing and storage industries, or pool safety alarms etc. Advantageously, the device or system can be used in detecting foreign bodies or contaminants.

[0068] EMBODIMENTS

[0069] The following are non-limiting embodiments of the present invention, and is presented for purposes of illustration and description, and is not intended to limit the invention to the systems and/or devices disclosed herein.

[0070] Embodiment 1 : According to an embodiment of the present invention, there is provided an ultrasonic pool occupant sensing device, capable of using ultrasonic pulses to analyze an occupancy level of a pool, comprising:

a. an ultrasonic transducer, capable of sending and receiving ultrasonic pulses, wherein the transducer emits an ultrasonic pulse when activated by an electronic pulse, wherein the transducer generates an electronic signal when it receives an ultrasonic pulse;

b. a front end electronics system, operatively connected to the ultrasonic transducer, wherein the front end electronics system processes incoming and outgoing electronic signals from the transducer, comprising:

i. a driver capable of sending the electronic pulse to the transducer;

ii. a low-noise pre-amplifier, capable of receiving the electronic signal from the transducer;

iii. a band-pass filter, operatively connected to the pre-amplifier, capable of filtering the electronic signal from the transducer; and

iv. an amplifier, operatively connected to the band-pass filter, capable of amplifying the electronic signal receiver from the band-pass filter; and a. a digital processing system comprising:

i. a timer unit, configured to signal the driver to generate the electronic pulse at intervals;

ii. an input/output unit, capable of sending and receiving data to and from the front-end electronics system and the processing system;

iii. an analog to digital converter, configured to convert the electronic signal received from the transducer from analog to digital; and

iv. a signal processor, configured to analyze the electronic signal and produce data concerning a number of occupants in the range of the transducer;

wherein the pool occupant sensing device is placed inside the pool, wherein the timer unit of the digital processing unit sends a timing signal to the driver of the front end electronics, whereupon the driver generates the electronic pulse, whereupon the electronic pulse is transmitted to the ultrasonic transducer,

whereupon the ultrasonic transducer emits an ultrasonic pulse which is transmitted into the pool at intervals, wherein the ultrasonic pulse is reflected off of the walls and occupants within the pool, whereupon the transducer receives an echo of the pulse, wherein the echo of the pulse is distorted by reflection from the various occupants and walls of the pool, wherein the transducer generates a received electronic signal, wherein the received electronic signal is passed through the pre-amplifier, band-pass filter, and amplifier of the front end electronics, wherein the received signal is transmitted to the digital processing unit, wherein the digital processing unit passes the signal through the analog-to-digital converter to produce a digital signal of the pulse, whereupon the signal processor generates data concerning the number of occupants in the pool, wherein the input/output unit permits the data to be transmitted to an external processor.

[0071] Embodiment 2: The device of Embodiment 1 , wherein the signal processor compares data derived from the ultrasonic pulse transmitted into the pool at intervals to determine a change in the occupancy level.

[0072] Embodiment 3: The device of Embodiment 1 or 2, wherein the external processor is operatively connected to a visual display unit to display the aggregate estimate of the total number of occupants and/or the position of occupants in the pool.

[0073] Embodiment 4: A pool occupancy level system comprising at least one ultrasonic pool occupant sensing device of Embodiment 1 , wherein the external processor collects data from each pool occupant sensing device, whereupon the external processor generates an aggregate estimate of the total number of occupants in the pool.

[0074] Embodiment 5: The system of Embodiment 4, comprising a plurality of pool occupant sensing devices, wherein the pool occupant sensing devices communicate data and commands between them exploiting ultrasound waves travelling into water.

[0075] Embodiment 6: According to another embodiment of the present invention, there is provided a pool-water regulation system, based on sonar detection of a number of occupants in a pool, comprising:

a. a central processing unit;

b. at least one ultrasonic pool occupant sensing device, operatively connected to the central processing unit, disposed inside a pool; and c. a pool water circulation control system, capable of adjusting the rate at which water is pumped through the pool and the amount of additives added, operatively connected to the central processing unit;

whereupon the central processing unit collects data from each ultrasonic pool occupant sensing device, whereupon the central processing unit generates an aggregate estimate of the total number of occupants in the pool, whereupon the central processing unit controls the pool water circulation system to adjust the additive dispensation and pump rate of the circulation system according to the number of occupants in the pool.

[0076] Embodiment 7: The system of Embodiment 6, wherein the pool occupant sensing devices are arranged to form a grid across the pool, wherein the central processing unit determines how many occupants are in each section of the grid, wherein the pool circulation in each grid section is independently controlled.

[0077] Embodiment 8: The system of Embodiment 6 or 7, comprising a plurality of pool occupant sensing devices, wherein the pool occupant sensing devices communicate data and commands between them exploiting ultrasound waves travelling into water.

[0078] Embodiment 9: The system of any one of Embodiment 6 to 8, wherein the additives comprise cleaning chemicals or solutions.

[0079] Embodiment 10: The system of any one of Embodiments 4 to 9, when used in a pool for human occupancy.

[0080] Embodiment 1 1 : The system of any one of Embodiments 6 to 8, where the additives comprise feed.

[0081] Embodiment 12: The system of any one of Embodiments 4 to 9 or 1 1 , when used in a fishery or in an aqua-cultural farm.

[0082] Embodiment 13: The system of any one of Embodiments 4 to 9 or 1 1 , when used in a food or beverage industries. [0083] Embodiment 14: The system of any one of Embodiments 4 to 9 or 1 1 , when used in fluid processing or refining industries.

[0084] Embodiment 15: The system of any one of Embodiments 4 to 9 or 1 1 , when used in storage industries.

[0085] Embodiment 16: According to another embodiment of the present invention, there is provided an ultrasonic pool occupant sensing device, capable of using ultrasonic pulses to analyze an intrusion in a pool, comprising:

a. an ultrasonic transducer, capable of sending and receiving ultrasonic pulses, wherein the transducer emits an ultrasonic pulse when activated by an electronic pulse, wherein the transducer generates an electronic signal when it receives an ultrasonic pulse;

b. a front end electronics system, operatively connected to the ultrasonic transducer, wherein the front end electronics system processes incoming and outgoing electronic signals from the transducer, comprising:

i. a driver capable of sending the electronic pulse to the transducer;

ii. a low-noise pre-amplifier, capable of receiving the electronic signal from the transducer;

iii. a band-pass filter, operatively connected to the pre-amplifier, capable of filtering the electronic signal from the transducer; and

iv. an amplifier, operatively connected to the band-pass filter, capable of amplifying the electronic signal receiver from the band-pass filter; and c. a digital processing system comprising:

i. a timer unit, configured to signal the driver to generate the electronic pulse at intervals;

ii. an input/output unit, capable of sending and receiving data to and from the front-end electronics system and the processing system;

iii. an analog to digital converter, configured to convert the electronic signal received from the transducer from analog to digital; and

iv. a signal processer, configured to analyze the received digital signal and produce data concerning a number of people in the range of the transducer; wherein the pool occupant sensing device is placed inside the pool, wherein the timer unit of the digital processing unit sends a timing signal to the driver of the front end electronics, whereupon the driver generates the electronic pulse, whereupon the electronic pulse is transmitted to the ultrasonic transducer,

whereupon the ultrasonic transducer emits an ultrasonic pulse which is transmitted into the pool at intervals, wherein the ultrasonic pulse is reflected off the walls and intrusion within the pool, whereupon the transducer receives an echo of the pulse, wherein the echo of the pulse is distorted by reflection from the intrusion and walls of the pool, wherein the transducer generates a received electronic signal, wherein the received electronic signal is passed through the pre-amplifier, band-pass filter, and amplifier in the front end electronics, wherein the received signal is transmitted to the digital processing unit, wherein the digital processing unit passes the signal through the analog-to-digital converter to produce a digital signal of the pulse, whereupon the signal processor generates data concerning the presence of the intrusion in the pool, wherein the input/output unit permits the data to be transmitted to an alarm system.

[0086] Embodiment 17: The device of Embodiment 16, wherein the signal processor compares data derived from the ultrasonic pulse transmitted into the pool at intervals to determine a change in the status of the intrusion in the pool.

[0087] Embodiment 18: The device of Embodiment 16 or 17, wherein the signal processor compares data derived from the ultrasonic pulse transmitted into the pool at intervals to determine any change in the status of the pool.

[0088] Embodiment 19: The device of any one of Embodiments 16 to 18, wherein data is transmitted to a visual display unit to display the aggregate estimate the position of the intrusion in the pool.

[0089] Embodiment 20: The device of any one of Embodiments 16 to 18, wherein the alarm system is a remotely located alarm system.

[0090] Embodiment 21 : The device of Embodiment 20, wherein data is transmitted to the remotely located alarm system wirelessly. [0091] Embodiment 22: The device of any one of Embodiments 16 to 21 , when used in a pool for human occupancy.

[0092] Embodiment 23: A pool intrusion system comprising one or more ultrasonic pool occupant sensing devices of any one of Embodiments 16 to 22.

[0093] Embodiment 24: The system of Embodiment 23, wherein the pool occupant sensing devices communicate data and commands between them wirelessly.

[0094] Embodiment 25: The system of Embodiment 24, wherein the pool occupant sensing devices communicate data and commands between them exploiting ultrasound waves travelling into water.

[0095] As used herein, the term "about" refers to plus or minus 10% of the referenced number.

[0096] Various modifications of the invention, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in the present application is incorporated herein by reference in its entirety.

[0097] Although there has been shown and described the preferred embodiment of the present invention, it will be readily apparent to those skilled in the art that modifications may be made thereto which do not exceed the scope of the appended claims. Therefore, the scope of the invention is only to be limited by the following claims. Reference numbers recited in the claims are exemplary and for ease of review by the patent office only, and are not limiting in any way. In some embodiments, the figures presented in this patent application are drawn to scale, including the angles, ratios of dimensions, etc. In some embodiments, the figures are representative only and the claims are not limited by the dimensions of the figures. In some embodiments, descriptions of the inventions described herein using the phrase "comprising" includes embodiments that could be described as "consisting of, and as such the written description requirement for claiming one or more embodiments of the present invention using the phrase "consisting of is met.