Ultrasonic liquid level sensing

Abstract

Systems and methods for ultrasonic liquid level sensing. Circuitry causes an ultrasonic transducer to emit a sequence of ultrasonic pulses and receive a sequence of reflected signals. Each reflected signal includes at least one first reflection associated with at least one immovable surface and at least one second reflection associated with a movable surface. For each reflected signal, a digital controller: determines at least one of an amplitude and a variance of the respective signal to form at least one output signal; identifies, in the at least one output signal, at least one first pulse indicative of the at least one immovable surface and at least one second pulse indicative of the movable surface; determines, based on the identified first and second pulses, a distance of the movable surface relative to the at least one immovable surface.

Description

[0001] Cross-referencing related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 168075, filed March 30, 2021, and U.S. Patent Application No. 17 / 707688, filed March 29, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to ultrasonic pulse echo range sensing, and more specifically, to ultrasonic level sensing systems and methods for automatically controlling the distribution of liquid into a container using ultrasonic sensors. Background Technology

[0004] Dispensing systems for dispensing one or more liquids (e.g., water, coffee, soft drinks, mixed drinks, etc.) into containers are known. Liquid dispensing systems can be used in domestic and / or commercial applications. For example, dispensers may include stand-alone units (e.g., for dispensing soft drinks, coffee, etc.) and / or may be integrated into other units (e.g., refrigerators, faucets, other appliances, etc.).

[0005] Some dispensers are considered automatic because they allow users to input certain characteristics of the container (e.g., container size, container type, such as a water bottle or glass). However, traditional automatic dispensers typically rely on the user to start and / or stop the dispensing of liquids, for example, by pressing some type of button and / or lever. Because traditional automatic dispensers usually involve some kind of interaction between the user and the dispenser to control the dispensing of liquids, there is a potential for the spread of pathogens from person to person through the dispensing system, resulting in an unsanitary and unsafe operating environment.

[0006] Therefore, the desired solution is to provide contactless automatic filling (i.e., liquid dispensing control without any user interaction) to offer an improved, hygienic operating environment. Traditional contactless dispensers utilize sensor systems to automatically fill containers. However, these traditional contactless dispensers currently present challenges. For example, some traditional dispensers struggle and / or are simply unable to monitor liquid levels and adequately fill containers of varying sizes (e.g., height and / or width) and / or shapes (e.g., uniform shapes like cylinders, non-uniform shapes like conical containers, containers with multiple non-uniform surfaces like animal-shaped containers) to the desired level. Furthermore, traditional contactless dispensers typically rely on multiple sensors and complex processing techniques across one or more areas of the dispenser to achieve automatic filling.

[0007] Therefore, there is a need for non-contact automatic liquid dispensers with improved level sensing and dispensing control. Summary of the Invention

[0008] Various aspects of this disclosure relate to systems and methods for ultrasonic level sensing.

[0009] In some implementations, an ultrasonic sensor can be used to automatically fill a container with liquid. In some implementations, the ultrasonic sensor can be provided as part of a liquid dispenser system and can be used to detect when a container is placed under a liquid dispenser to control the liquid dispenser to fill the container with liquid and to stop the liquid dispenser before the container overflows.

[0010] In some embodiments, a system for monitoring a movable surface is disclosed, the system comprising: an ultrasonic transducer; circuitry coupled to the ultrasonic transducer; and a digital controller. The circuitry is configured to cause the ultrasonic transducer to emit a sequence of ultrasonic pulses and to receive a sequence of reflected signals in response to the emitted ultrasonic pulse sequence. Each reflected signal in the reflected signal sequence includes at least one first reflection and at least one second reflection. The at least one first reflection is associated with at least one immovable surface. The at least one second reflection is associated with a movable surface. The digital controller is configured, for each reflected signal in the reflected signal sequence: to determine at least one of the amplitude and variance of the corresponding reflected signal in the reflected signal sequence to form at least one output signal; to identify, in the at least one output signal, at least one first pulse indicating the at least one immovable surface and at least one second pulse indicating the movable surface; and to determine, based on the identified at least one first pulse and the identified at least one second pulse, the distance of the movable surface relative to the at least one immovable surface.

[0011] In some embodiments, the distance of the movable surface relative to the at least one immovable surface is determined based on at least one first time of flight (TOF) indicated by the at least one first pulse and a second time of flight (TOF) indicated by the at least one second pulse.

[0012] In some embodiments, the digital controller is configured to identify the at least one second pulse indicating a movable surface based on the variance of a corresponding reflected signal in a sequence of reflected signals. In some embodiments, the digital controller is configured to determine at least one of amplitude and variance based on the application of at least one predefined filter. In some embodiments, the digital controller is configured to identify the at least one first pulse indicating the at least one immovable surface based on the amplitude of a corresponding reflected signal in a sequence of reflected signals. In some embodiments, the digital controller is configured to determine the stability of the at least one immovable surface based on the variance of a corresponding reflected signal in a sequence of reflected signals.

[0013] In some implementations, the system is configured to determine the liquid level inside a container, the movable surface including the liquid level, and the at least one immovable surface including one or more of the container rim and the container bottom.

[0014] In some embodiments, the system is configured to determine a background signal via an ultrasonic transducer when the container is not present within a predetermined detection area. The background signal includes a ring-down component, and the digital controller is configured to subtract the background signal from the reflected signal sequence to minimize the ring-down component in the reflected signal sequence. In some embodiments, the system is configured to determine the background signal periodically. In some embodiments, the system is configured to determine one or more of the background signal and the presence of the container at a first sampling rate, and to utilize a second sampling rate, where the first sampling rate is lower than the second sampling rate, on the received reflected signal sequence.

[0015] In some embodiments, before emitting the ultrasonic pulse sequence, the system is configured to detect the presence of a container within a predetermined detection area via an ultrasonic transducer, and in response to the detection of a container, to initiate the dispensing of liquid into the container. In some embodiments, a digital controller is configured to monitor the liquid level based on a determined distance, and to stop dispensing liquid when the determined distance is within a predetermined threshold relative to the edge of the container.

[0016] In another aspect, a method for ultrasonically monitoring a movable surface is disclosed. In one embodiment, a method for monitoring a movable surface is provided, comprising: causing an ultrasonic transducer to emit a sequence of ultrasonic pulses via circuitry coupled to the ultrasonic transducer; and receiving a sequence of reflected signals in response to the emitted ultrasonic pulse sequence via circuitry. Each reflected signal in the sequence of reflected signals includes at least one first reflection and at least one second reflection. The at least one first reflection is associated with at least one immovable surface. The at least one second reflection is associated with a movable surface. The method further comprises, for each reflected signal in the sequence of reflected signals: determining at least one of the amplitude and variance of the corresponding reflected signal in the sequence of reflected signals via a digital controller to form at least one output signal; identifying at least one first pulse indicating the at least one immovable surface and at least one second pulse indicating the movable surface in the at least one output signal via the digital controller; and determining, via the digital controller, the distance of the movable surface relative to the at least one immovable surface based on the identified at least one first pulse and the identified at least one second pulse.

[0017] In some embodiments, the distance of the movable surface relative to the at least one immovable surface is determined based on at least one first time of flight (TOF) indicated by the at least one first pulse and a second time of flight (TOF) indicated by the at least one second pulse.

[0018] In some embodiments, identifying the at least one first pulse and the at least one second pulse further includes: identifying the at least one second pulse indicating a movable surface based on the variance of the corresponding reflected signals in the reflected signal sequence. In some embodiments, determining the at least one of amplitude and variance includes applying at least one predefined filter. In some embodiments, identifying the at least one first pulse and the at least one second pulse further includes: identifying the at least one first pulse indicating the at least one immovable surface based on the amplitude of the corresponding reflected signals in the reflected signal sequence. In some embodiments, identifying the at least one first pulse and the at least one second pulse further includes: determining the stability of the at least one immovable surface based on the variance of the corresponding reflected signals in the reflected signal sequence.

[0019] In some embodiments, the movable surface includes the liquid level, and the at least one immovable surface includes one or more of the container edge and the container bottom, the container being configured to contain liquid, and determining the distance of the movable surface relative to the at least one immovable surface includes determining the liquid level inside the container.

[0020] In some embodiments, the method further includes determining a background signal via an ultrasonic transducer when the container is not present within a predetermined detection area. The background signal includes a ring-down component, and the background signal is subtracted from the reflected signal sequence via a digital controller to minimize the ring-down component in the reflected signal sequence. In some embodiments, the method further includes periodically determining the background signal. In some embodiments, the method further includes: determining one or more of the background signal and the presence of the container at a first sampling rate; and applying a second sampling rate to the received reflected signal sequence, the first sampling rate being lower than the second sampling rate.

[0021] In some embodiments, the method further includes, before emitting the ultrasonic pulse sequence: detecting the presence of a container within a predetermined detection area via an ultrasonic transducer; and, in response to detecting the container, causing a dispenser to begin dispensing liquid into the container. In some embodiments, the method further includes: monitoring the liquid level via a digital controller based on a determined distance; and causing the dispenser to stop dispensing liquid when the determined distance is within a predetermined threshold relative to the edge of the container.

[0022] In another aspect, an apparatus for dispensing liquid in a container is disclosed. In one embodiment, the apparatus for dispensing liquid in a container includes: a dispenser configured to dispense liquid into the container; at least one time-of-flight (TOF) sensor; circuitry coupled to the at least one TOF sensor; and a digital controller. The circuitry is configured to cause the at least one TOF sensor to emit a sequence of pulses and receive a sequence of reflected signals. Each reflected signal in the sequence of reflected signals includes at least one first reflection and at least one second reflection. The at least one first reflection is associated with a portion of the container. The at least one second reflection is associated with the level of liquid dispensed into the container. The portion of the container includes at least one of an edge and a bottom surface. The digital controller is configured, for each signal in the sequence of reflected signals: to determine at least one of the amplitude and variance of the corresponding reflected signal in the sequence of reflected signals to form at least one output signal; in the at least one output signal, to identify at least one first pulse indicating the portion of the container and at least one second pulse indicating the liquid level; and to determine the distance of the liquid level relative to the portion of the container based on the identified at least one first pulse and the identified at least one second pulse. The digital controller is configured to monitor changes in liquid level on a sequence of reflected signals based on a defined distance in order to control the distribution of liquid via the dispenser.

[0023] In some implementations, the digital controller is configured to cause the dispenser to stop dispensing liquid when a determined distance relative to the edge of the container is within a predetermined threshold.

[0024] In some implementations, prior to emitting the pulse sequence, the system is configured to detect the presence of a container within a predetermined detection area via the at least one TOF sensor, and in response to detecting the container, to cause the dispenser to begin dispensing liquid into the container.

[0025] In some implementations, the system is configured to determine a background signal via the at least one TOF sensor when the container is not present in a predetermined detection area. The background signal includes a ring-down component, and the digital controller is configured to subtract the background signal from the reflected signal sequence to minimize the ring-down component in the reflected signal sequence.

[0026] In some embodiments, the digital controller is configured to identify the at least one second pulse indicating a change in liquid level based on the variance of the corresponding reflected signals in the reflected signal sequence. In some embodiments, the digital controller is configured to: identify the at least one first pulse indicating a portion of the container based on the amplitude of the corresponding reflected signal in the reflected signal sequence; and determine the stability of the container based on the variance of the corresponding reflected signals in the reflected signal sequence. In some embodiments, the at least one TOF sensor includes at least one of an ultrasonic sensor, a radar sensor, and an optical sensor. Attached Figure Description

[0027] An embodiment of the non-contact ultrasonic liquid dispenser and ultrasonic liquid level sensing method is shown in the accompanying drawings.

[0028] Figure 1 This is a schematic view illustrating an exemplary non-contact liquid dispenser according to one aspect of this disclosure.

[0029] Figure 2 This is a functional block diagram illustrating an exemplary dispenser system according to one aspect of this disclosure.

[0030] Figure 3A This is a side view showing an exemplary acoustic horn that can be used with an ultrasonic sensor according to one aspect of this disclosure.

[0031] Figure 3B This is based on one aspect of this disclosure. Figure 3A The image shows a top view of an acoustic horn.

[0032] Figure 3C According to one aspect of this disclosure, along Figure 3A The cross-sectional view of the acoustic horn obtained from the 3C-3C line is shown.

[0033] Figure 4 This is a flowchart illustrating an exemplary method for controlling the dispensing of liquid into a container, according to one aspect of this disclosure.

[0034] Figure 5 This is a flowchart illustrating an exemplary method for determining surface distances via ultrasonic measurement, according to one aspect of this disclosure.

[0035] Figure 6 This is a flowchart illustrating an exemplary method for calibrating a background signal according to one aspect of this disclosure.

[0036] Figure 7A This is a state diagram illustrating an exemplary state for controlling the dispensing of liquid into a container, according to one aspect of this disclosure.

[0037] Figure 7B It is a table that displays one aspect of this disclosure, and Figure 7A The state diagram shown is associated with exemplary events.

[0038] Figure 8A and 8B According to one aspect of this disclosure, an exemplary intensity map is a range of ultrasonic signals reflected as a function of the time of an empty distribution area (without a container) and an empty container positioned in the distribution area, respectively.

[0039] Figure 8C According to one aspect of this disclosure, an exemplary intensity map is provided as a function of the time of an amplitude-processed ultrasonic signal reflected by the container and the changing liquid level within the container as liquid is dispensed into the container over time.

[0040] Figure 8D According to one aspect of this disclosure, as by having Figure 8C An exemplary intensity graph showing the range of time of the ultrasonic signal reflected by the same container with varying liquid levels, processed by variance, as a function of time.

[0041] Figure 9A According to one aspect of this disclosure, the amplitude of the original ultrasonic reflected signal of the empty container and the empty dispenser region is used as an exemplary graph of the functional distance.

[0042] Figure 9B This is based on one aspect of this disclosure. Figure 9A The amplitudes of the filtered amplitude-processed and filtered variance-processed ultrasonic reflected signals of the empty container are shown as an exemplary graph of the functional distance.

[0043] Figure 9C According to one aspect of this disclosure, when Figure 9A and 9B The amplitudes of the filtered amplitude-processed and filtered variance-processed ultrasonic reflection signals of the container shown are used as an example graph of the function distance when the container is filled with liquid at a specific time. Detailed Implementation

[0044] Various aspects of this disclosure relate to systems and methods for ultrasonic level sensing, including using an ultrasonic transducer (e.g., an ultrasonic sensor) to monitor the level of liquid in a container (e.g., a movable surface) to control the automatic filling (i.e., dispensing) of liquid into the container. As mentioned above, it is desirable to provide a non-contact automated liquid dispenser that can provide an improved hygienic operating environment. Furthermore, it is desirable to provide a level sensing solution that can ultrasonically monitor the liquid level in containers of different sizes and / or shapes and can stop dispensing liquid at a predetermined threshold, thereby preventing liquid from overflowing from the container. Additionally, it is desirable to provide a compact and robust level sensing solution that utilizes less ultrasound and / or other sensors positioned within a smaller footprint of the dispenser. Therefore, providing a compact and robust ultrasonic liquid sensing for non-contact automated liquid dispensing functionality is crucial.

[0045] In some embodiments, various aspects of this disclosure relate to systems and methods for monitoring movable surfaces (i.e., liquid levels). In some embodiments, the system may include an ultrasonic transducer, circuitry coupled to the ultrasonic transducer (e.g., a transmitter and a receiver), and a digital controller. In some embodiments, the circuitry may be configured to cause the ultrasonic transducer to emit a sequence of ultrasonic pulses and receive a sequence of reflected signals in response to the emitted ultrasonic pulse sequence. Each reflected signal in the sequence of reflected signals may include at least one first reflection and at least one second reflection, wherein the first reflection may be associated with at least one immovable surface (e.g., the edge and / or bottom of a container), and the at least one second reflection may be associated with a movable surface (e.g., the liquid level in the container). In some embodiments, the digital controller may be configured, for each reflected signal in the sequence of reflected signals: to determine at least one of the amplitude and variance of the corresponding reflected signal in the sequence to form at least one output signal; to identify in the output signal at least one first pulse indicating an immovable surface (e.g., the edge and / or the bottom) and at least one second pulse indicating a movable surface; and to determine, based on the identified first and second pulses, the distance of the movable surface (e.g., the liquid level) relative to the immovable surface (e.g., the edge and / or the bottom of the container).

[0046] In some embodiments, the system may represent a liquid dispensing system in which reflected ultrasonic pulses from an ultrasonic sensor can be used to automatically fill a container with liquid. In some embodiments, the system may also use reflected ultrasonic pulses via an ultrasonic transducer to detect the presence and / or stability of the container to control the initial dispensing of liquid into the container. In some embodiments, the system may repeatedly monitor the liquid level (via reflected ultrasonic pulses) during liquid dispensing and cause the dispenser to stop dispensing liquid when the liquid level is within a predetermined threshold at the edge.

[0047] In some embodiments, the system may be further configured to determine a background signal representing the dispenser's dispensing area (also referred to herein as a predetermined detection area) when no container is positioned within the dispensing area. The system may be further configured to subtract the background signal from the reflected ultrasonic pulses when a container is positioned within the dispensing area. In some embodiments, the system may be configured to periodically measure the background signal. In some embodiments, the system may be configured to further filter the received signal (which may form an output signal) after amplitude and / or variance processing. In some embodiments, the background signal may represent a ring-down signal.

[0048] In some embodiments, the amplitude-processed signal (i.e., which can form an output signal) can be used to detect the edges and bottom of the container. In some embodiments, the variance-processed signal (i.e., which can form an output signal) can be used to monitor the (changing) liquid level in the container.

[0049] In some embodiments, the system may utilize a single ultrasonic transducer to detect when a container (e.g., a cup, bottle, bowl, etc.) is placed under the liquid dispenser, control the liquid dispenser to automatically fill the container to the desired fill level, and stop the dispenser before liquid overflows. By utilizing a single ultrasonic transducer to emit and receive ultrasonic pulses to detect movable surfaces (i.e., changing liquid levels) and immovable surfaces (i.e., the edges and / or bottom of the container), the system disclosed herein provides a cost-effective, compact, and minimal-footprint solution for contactless automated liquid dispensing. This contrasts sharply with conventional contactless automated dispensers, which may require multiple ultrasonic transceivers (and / or other combinations of sensors) in different areas of the dispenser to control the dispensing of liquid into containers, and conventional solutions may be inadequately operable (or completely inoperable) for containers of different sizes and / or shapes.

[0050] Although embodiments of the liquid level sensing and non-contact automatic liquid dispenser of this disclosure are described herein in relation to ultrasonic sensing with an ultrasonic sensor, the liquid sensing and liquid dispenser are not limited to ultrasonic sensors. In general, the liquid sensing technology and liquid dispenser of this disclosure can utilize any suitable time-of-flight (TOF) sensor, including ultrasonic sensors, optical sensors, and / or radar sensors.

[0051] Next reference Figure 1 The diagram illustrates an exemplary non-contact automatic liquid dispenser 100 (referred to herein as dispenser 100). Dispenser 100 may include a dispenser housing 102 having a body 104 and a top portion 106. The body 104 may include a base surface 108. The body 104 and the top portion 106 may be configured to form a dispensing area 110 therein.

[0052] The upper portion 106 can be configured to include an ultrasonic transducer 112 and a dispenser nozzle 114. In some embodiments, the ultrasonic transducer 112 can be positioned adjacent to the dispenser nozzle 114, such that the dispenser 100 can be configured to operate with containers having both a smaller opening (e.g., a bottle) and a larger opening (e.g., a bowl). Although Figure 1The ultrasonic transducer 112 is positioned adjacent to (e.g., next to) the dispenser nozzle 114, but it is understood that the position of the ultrasonic transducer 112 relative to the dispenser nozzle 114 is not limited thereto, and in some embodiments, the ultrasonic transducer 112 may be separated from the dispenser nozzle 114 by any suitable predetermined distance.

[0053] In some embodiments, the ultrasonic transducer 112 may include a micromachined ultrasonic transducer. In some embodiments, the ultrasonic transducer 112 may include a membrane formed on a substrate, which may be actuated using one or more of piezoelectric, capacitive, and thermal actuation. Generally, the dimensions of the ultrasonic transducer 112 (e.g., the surface area of ​​the membrane) and / or the characteristics of the ultrasonic transducer 112 (e.g., membrane thickness, membrane tension, membrane material, etc.) can be selected to generate ultrasonic pulses to properly detect the container 118 and the liquid level 126 within the container 118. The dispenser nozzle 114 may include any suitable nozzle for dispensing liquid 124 into the container 118. In some embodiments, the ultrasonic transducer may include an acoustic horn (e.g., Figures 3A-3C The acoustic speaker 300 shown.

[0054] Dispenser 100 can be configured such that container 118 can be placed within dispensing area 110 (e.g., a predetermined detection area). Generally, container 118 may include a bottom 120 and an edge 122. In some embodiments, container 118 may be placed on a base surface 108 of body 104. In some embodiments, container 118 may be held by a user within dispensing area 110 (e.g., not positioned on base surface 108). Generally, container 118 may include any type of container (e.g., cup, bowl, bottle, etc.) configured to contain liquid 124. Container 118 can be any variable size and / or variable shape, as long as container 118 can be positioned within dispensing area 110 such that liquid 124 can be guided into container 118 through edge 122.

[0055] The ultrasonic transducer 112 can be configured to transmit and receive ultrasonic pulses, typically indicated by a double-headed arrow as pulse 116. The transmitted pulse 116 can be directed toward the dispensing area 110. Generally, the transmitted pulse 116 can be reflected by the container 118 (when placed within the dispensing area 110) or by the liquid level 126 of the liquid 124 (when the container 118 contains liquid 124). In some embodiments, the dispensing area 110 can be empty (i.e., may not include any container 118 placed therein), and the transmitted pulse 116 can be reflected by the dispensing area 110 (without a container). When the dispensing area 110 has no container 118, the reflected pulse 116 can represent a background signal indicating a drop in the ring.

[0056] Generally, the membrane of the ultrasonic transducer 112 can vibrate when the ultrasonic transducer 112 emits a pulse. In some embodiments, the membrane can continue to vibrate for a short period after the pulse is emitted, eventually decaying to zero (i.e., no) displacement. The vibration caused by the emitted pulse typically has a high amplitude, referred to as a "ringdown". The ringdown can limit the ability of the ultrasonic transducer 112 to detect echoes (reflections) from nearby objects. This is because the ringdown signal is typically several orders of magnitude larger than the returned echo signal. The time period associated with the ringdown of the ultrasonic transducer 112 may correspond to a blind spot referred to herein as the "ringdown region". The ringdown region can represent the area between the ultrasonic transducer 112 and the nearest distance from which the object can be detected using the returned (reflected) signal corresponding to the signal emitted by the ultrasonic transducer 112.

[0057] In operation, the ultrasonic transducer 112 can be configured to emit and receive one or more ultrasonic pulses 116. The received pulses 116 can be used to detect the presence of a container 118 in the dispensing area 110. The received pulses 116 can also be used to determine the bottom position of the bottom 120 and the edge position of the edge 122 of the container 118 when the container 118 is empty (e.g., before the dispensing of liquid 124). Once the container 118 is detected and the edge and bottom positions are known, the dispensing of liquid 124 can begin, and liquid 124 can be dispensed from the dispenser nozzle 114 into the container 118.

[0058] Synchronized with the dispensing of liquid 124, ultrasonic transducer 112 can be configured to emit and receive one or more time-varying pulses 116 (i.e., a time-varying sequence of pulses 116). The reflected pulses obtained during the dispensing of liquid 124 can be used to monitor the liquid level 126 within container 118 as the liquid level 126 changes (e.g., increases) over time. In some embodiments, dispenser 100 can determine and monitor the distance D1 between the edge position and the liquid level position based on the sequence of reflected pulses 116 and a determined edge position. In some embodiments, dispenser 100 can use additional information from distance D2 (between the edge position and the dispenser base position) and / or distance D3 (between the liquid level position and the dispenser base position) to monitor the liquid level 126. For example, D2 and / or D3 can be utilized (and in some embodiments, measured periodically) when container 118 is held by hand rather than placed on the base surface 108 of body 104.

[0059] Liquid 124 may continue to be dispensed by dispenser nozzle 114 until liquid level 126 is determined to be within a predetermined threshold of edge 122 (e.g., within a predetermined threshold at the edge location). In this way, the (changing) position of liquid level 126 relative to edge 122 (i.e., D1), in some embodiments, one or more of D2 and D3, may be used to determine when to automatically stop dispensing liquid 124 through dispenser nozzle 114.

[0060] Further details regarding the determination of the bottom position, edge position, and liquid level position are provided below. Figure 4-9C To describe. In some embodiments, dispenser 100 may include dispenser system 200 for controlling ultrasonic transducer 112 and dispenser nozzle 114 and for automatically detecting and monitoring liquid level 126 in container 118. Figure 2 (as described below).

[0061] Generally, dispenser 100 can be configured to use ultrasonic transducer 112 to provide (non-contact) automatic detection of liquid level 126 in container 118. In some embodiments, ultrasonic transducer 112 may represent a single ultrasonic transducer 112 that can provide automatic monitoring of liquid level 126, thereby providing a compact, cost-effective, and efficient computational solution for contactless automatic liquid dispensing. Dispenser 100 may be part of a standalone liquid dispenser (e.g., a water dispenser) or a liquid dispenser integrated into another device (e.g., a refrigerator). Dispenser 100 may be configured for commercial and / or residential use. The dispensed liquid 124 can be of any suitable temperature. In some embodiments, a temperature sensor (not shown) may be included in dispenser 100 to indicate the temperature of the liquid. In some embodiments, dispenser 100 may include a display (e.g., a... Figure 2 The display unit 228 shown is used to display any appropriate information associated with the dispensing of liquid 124 (e.g., the amount of liquid 124 being dispensed, fill level, temperature, etc.). In some embodiments, the dispenser 100 may include a user interface (e.g., Figure 2 The user interface 230 shown is used for user interaction with the dispenser 100 (e.g., for selecting a liquid, selecting the liquid's properties, etc.).

[0062] Figure 2 This is a functional block diagram illustrating an exemplary dispenser system 200 (hereinafter referred to as system 200) according to one aspect of this disclosure. System 200 may include a container / liquid sensing system 202 (hereinafter referred to as sensing system 202) and a liquid dispensing system 204. In some embodiments, system 200 may include one or more of an optional display unit 228 and a user interface 230.

[0063] The sensing system 202 may include an ultrasonic transducer 112, transceiver circuitry 206, a central computing unit 214, and one or more interfaces 220. In some embodiments, the sensing system 202 may include one or more optional time-of-flight (TOF) sensors 222. In some embodiments, the sensing system 202 may utilize another TOF sensor instead of the ultrasonic transducer 112 (e.g., an optical sensor and / or a radar sensor). Generally, liquid sensing technology (see...) Figure 4-6 (Detailed description) This can also be performed using TOF sensors other than ultrasonic sensors, including optical sensors and radar sensors. In some embodiments, the sensing system 202 may include one or more integrated circuits, or it may include discrete components.

[0064] Transceiver circuitry 206 may include transmitter 208, receiver 210, and state machine 212. Transceiver circuitry 206 may be configured to cause ultrasonic transducer 112 to transmit and receive one or more ultrasonic pulses. In some embodiments, but not limited thereto, ultrasonic transducer 112 (and other components of sensing system 202) may be configured as described in International Patent Application No. PCT / US2015 / 043256, filed July 31, 2015 and published as International Application WO2016 / 019317 on February 4, 2016, the entire contents of which are incorporated herein by reference. In some embodiments, but not limited thereto, transceiver circuitry 206 may be configured as described in U.S. Patent No. 10,634,544 ('544 Patent), granted April 28, 2020, the entire contents of which are incorporated herein by reference. In some embodiments, sensing system 202 may include one or more additional components described in '544 Patent (also incorporated herein by reference).

[0065] In some embodiments, transmitter 208 may include a buffer (e.g., a first-in-first-out (FIFO)), an output modulator, an amplifier, a transmit switch, and a programmable charge pump. The buffer may store transmit commands to control the output modulator to generate an output signal with desired amplitude, phase, and duration. The amplifier (along with the transmit switch) may be configured to control the output voltage signal applied to the ultrasonic transducer 112. The programmable charge pump may be configured to boost the input voltage supply level to a desired output range.

[0066] In some embodiments, receiver 210 may include a receive switch, a low-noise receive amplifier, a receive buffer (e.g., a FIFO register, an index register set), an analog-to-digital converter (ADC), and a mixer / filter block. The receive switch may be configured to block high-voltage transmit signals from the low-noise receive amplifier. The receive buffer may store receive commands for controlling the gain and time constant of the low-noise receive amplifier and the ADC. In some embodiments, the receive buffer may be omitted. The input signal received by receiver 210 from ultrasonic transducer 112 may be amplified and digitized by the low-noise amplifier and the ADC, respectively. The digital output signal (from the ADC) may be quadrature demodulated and filtered by the mixer / filter block.

[0067] In some embodiments, state machine 212 may be configured to control transmitter 208 and receiver 210. For example, state machine 212 may control the sequence of transmission and reception of ultrasonic signals by controlling components of transmitter 208 and receiver 210 (e.g., transmit buffer, output modulator, transmit switch, receive switch, and receive buffer).

[0068] In some embodiments, state machine 212 may retrieve commands from the transmit buffer and control transmitter 208 to execute commands for a specified duration within each command (e.g., until the transmit buffer is empty). State machine 212 may also retrieve commands from the receive buffer and control receiver 210 to execute commands for a specified duration within each command (e.g., until the receive buffer is empty). In some embodiments, transmit and receive commands may be generated by control unit 214 for measuring background signals, detecting the presence of container 118 in distribution area 110, and sensing and monitoring liquid level 126 in container 118.

[0069] State machine 212 can be implemented in software as a program that executes on a computer processor (e.g., processor 216), or in hardware as a sequential logic circuit implemented on, for example, a dedicated controller (ASIC), a field-programmable gate array (FPGA), or a system-on-a-chip (SoC). In some embodiments, state machine 212 can operate autonomously, but occasionally it may include interactions from central computing unit 214.

[0070] The central computing unit 214 may include at least one processor 216 and at least one non-transitory memory 218. In some embodiments, the central computing unit 214 may represent a digital controller.

[0071] In some embodiments, processor 216 may include, but is not limited to, a microprocessor, a central processing unit, an ASIC, an FPGA, a digital signal processor (DSP), a SoC, and / or a network processor. Processor 216 may be configured to execute processing logic for performing the operations described herein.

[0072] Memory 218 may include, for example, but not limited to, at least one of read-only memory (ROM), random access memory (RAM), flash memory, dynamic RAM (DRAM), and static RAM (SRAM), storing computer-readable instructions executable by processor 216. Memory 218 may include a non-transitory computer-readable storage medium storing computer-readable instructions executable by processor 216 for performing the operations described herein. In some embodiments, memory 218 may include data memory and program memory. Receiver 210 may be configured to output composite baseband data, which may be stored in the data memory portion of memory 218. Processor 216 may be configured to communicate with the data memory and, as referenced below... Figure 4-9C Further description of ultrasonic sensing and liquid distribution control algorithms for processing composite baseband data (these algorithms can be stored as computer-readable instructions in the program memory component of memory 218).

[0073] In some embodiments, processor 216 may be configured to control one or more of transceiver circuitry 206, liquid dispensing system 204, optional display unit 228, and optional user interface 230 via interface 220. In some embodiments, processor 216 may be configured to receive user input via optional user interface 230. Interface 220 may include any suitable interface for communication between sensing system 202, liquid dispensing system 204, and (in some embodiments) one or more of optional display device 228 and optional user interface 230.

[0074] Generally, sensing system 202 can determine the time of flight (TOF) to at least one object (e.g., container 118) using emitted and reflected ultrasonic pulses (obtained via ultrasonic transducer 112). The TOF can then be converted to a distance (e.g., range) to the object based on the speed of sound. For example, transceiver circuitry 206 can cause ultrasonic transducer 112 to emit ultrasonic pulses. When the emitted ultrasonic pulse is reflected from the object, the object can be detected based on the reflected echo (e.g., if the object is present and within detectable range). TOF, the time elapsed from emitting the original pulse to receiving the reflected echo, can be used to detect the distance of the object from ultrasonic transducer 112. Using a known value of the speed of sound c, the range can be calculated as range = TOF * c / 2. The concept of determining the distance to an object can be used to determine the distance between the edge of the container and the liquid level in the container to control the dispensing of liquid into the container by liquid dispensing system 204.

[0075] In some embodiments, the sensing system 202 may include at least one optional TOF sensor 222 (e.g., in addition to the ultrasonic transducer 112). In some embodiments, the optional TOF sensor 222 may be used to detect the presence of a container, determine the edge and / or bottom of the container (e.g., in place of the ultrasonic transducer 112), and / or may be used in conjunction with the ultrasonic transducer 112. For example, the optional TOF sensor 222 may be used to calibrate the TOF determined by the ultrasonic transducer 112, and / or as an accuracy check to ensure that liquid is stopped before it overflows from the container. The optional TOF sensor 222 may include any suitable sensor for determining the TOF value, including but not limited to one or more of ultrasonic sensors, optical sensors, and radar sensors. In some embodiments, the optional TOF sensor 222 may include an additional lateral sensor that may be used in conjunction with the ultrasonic transducer 112 to improve the detection of the container 118 in the dispensing area 110 (e.g., to better distinguish between container detection and no-container detection).

[0076] Liquid distribution system 204 may include dispenser nozzle 114, dispenser controller 224, and one or more liquid sources 226. Liquid sources 226 may include, but are not limited to, one or more reservoirs storing a certain amount of one or more liquids (e.g., water, soft drinks, coffee, etc.) and one or more continuous liquid sources (e.g., municipal water supply). Liquid from liquid source 226 may be configured to be dispensed via dispenser nozzle 114 in response to dispenser controller 224. Dispenser controller 224 may receive one or more commands (e.g., instructions) from sensing system 202 (via interface 220). In response to a received command, dispenser controller 224 may start and / or stop the flow of liquid through dispenser nozzle 114 (e.g., via control of one or more valves between liquid source 226 and dispenser nozzle 114). In some embodiments, dispenser controller 224 may be configured to select one or more liquid sources 226 based on user input via optional user interface 230 (e.g., to dispense a type of liquid or a combination of liquids).

[0077] The optional display unit 228 can be configured to display information determined by the sensing system 202 to the user. For example, the display unit 228 may display one or more indications relating to, but not limited to, container detection, detection of errors in the container, container stability, errors in container stability, start of liquid dispensing, end of liquid dispensing, liquid level in the container, remaining amount of liquid to be dispensed, estimated time to complete liquid dispensing, liquid temperature, instructions for using the dispenser, etc.

[0078] The optional user interface 230 can be configured to receive user input for one or more operations. In some embodiments, the optional user interface 230 may be a touchscreen and / or may be integrated with the optional display unit 228. In some embodiments, the optional user interface 230 may include one or more buttons and / or levers. In some embodiments, the optional user interface 230 may allow the user to indicate one or more of the following (but is not limited to): the type of container, the type of liquid to be dispensed, the temperature of the liquid to be dispensed, manual start and / or stop of the dispenser.

[0079] Next reference Figures 3A-3C An exemplary acoustic horn 300 according to one aspect of this disclosure is shown. Specifically, Figure 3A This is a side view of the acoustic speaker 300; Figure 3B This is a top view of the 300 acoustic loudspeaker; Figure 3C This is a cross-sectional view taken along line 3C-3C of the acoustic horn 300. In some embodiments, the ultrasonic transducer 112 ( Figure 1 It can be coupled to the acoustic horn 300 so that the ultrasonic pulse 116 can be transmitted and received through the acoustic channel formed by the acoustic horn 300.

[0080] The acoustic horn 300 may include at least one sidewall 302, a base surface 304, a mouth 306, and a throat 310. In some embodiments, the acoustic horn 300 may include one or more protrusions 308, for example, to help couple the base surface 304 of the acoustic horn 300 to the upper portion 106 of the distributor housing 102. Figure 1 The acoustic horn 300 may further include a recess 312 configured to receive the housing of the ultrasonic transducer 112. Figure 1 ).

[0081] In some embodiments, both the mouth 306 and the throat 310 may have a substantially circular shape, and the mouth 306 may have a larger diameter than the throat 310. In some embodiments, the acoustic horn may have an exponential shape (e.g., an exponentially increasing cross-sectional area from the throat 310 to the mouth 306). It is understood that the acoustic horn 300 is not limited to an exponential shape and may include any other suitable shape, such as, but not limited to, one or more of a basic parabolic, linear, hyperbolic, or conical shape.

[0082] As described above, the acoustic horn 300 provides an acoustic channel for guiding ultrasonic pulses 116 emitted from the ultrasonic transducer 112 toward the dispensing area 110 and for capturing ultrasonic pulses 116 reflected from the container 118 (liquid level 126 and / or empty dispensing area 110) and guiding the ultrasonic pulses to the ultrasonic transducer 112. In some embodiments, the acoustic horn 300 may be used to improve the directionality of the ultrasonic transducer 112 for emitting and receiving pulses 116. Figure 1 In some embodiments, the acoustic horn 300 can increase the acoustic energy incident on the ultrasonic transducer 112 from the received (reflected) pulse. In some embodiments, the acoustic horn 300 can improve the coverage area of ​​the ultrasonic pulse 116 in the distribution region 110.

[0083] Next reference Figure 4 A flowchart illustrating an exemplary method 400 for controlling the dispensing of liquid into a container is shown. Method 400 refers to... Figures 8A-8D This describes embodiments that provide reflected (and in some embodiments filtered) ultrasonic pulses for various distribution steps. Specifically, Figure 8A This is an exemplary intensity map showing the range of ultrasound signals reflected as a function of time from an empty distribution area (where no container exists); Figure 8B This is an exemplary intensity map showing the range of ultrasonic signals reflected as a function of the time of an empty container positioned in the distribution area; Figure 8CIt is an exemplary intensity map showing the range of an amplitude-processed ultrasonic signal reflected by the container and the changing liquid level in the container as liquid is dispensed into the container over time. Figure 8D It is composed of having and Figure 8C An exemplary intensity map showing the time range of the variance-processed ultrasonic signal reflected from the same container at varying liquid levels. Figures 8A-8C In the diagram, the intensity map represents the amplitude of the received in-phase and quadrature (IQ) data, and the intensity amplitude is expressed as a logarithmic magnitude. Figure 8D In the diagram, the intensity plot represents the variance of the IQ amplitude, and the intensity of the variance is represented as the low sideband (LSB) amplitude.

[0084] At step 402, one or more background signals can be determined via ultrasonic transducer 112. For example, when the dispensing area 110 of dispenser 100 does not include any container 118 presented therein, the background signal can be determined by sensing system 202. For example, as Figure 8A As shown, when no container is within the dispensing area 110, the ultrasonic transducer 112 can be configured to measure background signals of the surrounding environment and the dispenser housing 102 (e.g., the dispensing area 110). Figure 8A The background signal sequence measured over time primarily comprises one or more reflection components (such as ring drop component 802) that do not change significantly over time. In some embodiments, the background signal can be measured periodically, as referred to below. Figure 6 To describe.

[0085] At step 404, sensing system 202 can automatically detect the presence of container 118 via ultrasonic transducer 112. For example, based on characteristics and / or characteristic changes in the reflected ultrasonic pulse sequence, sensing system 202 can automatically determine when container 118 appears in dispensing area 110. In some embodiments, sensing system 202 can further determine whether the detected container 118 is placed on the base surface 108 of the dispenser housing or held by hand (i.e., handheld) based on the reflected ultrasonic pulse sequence. For example, minimal change in the characteristics of the reflected pulses may indicate that container 118 is placed directly on dispenser housing 102. Conversely, variability in the reflected ultrasonic pulses over time may indicate that container 118 is handheld. As used herein, ultrasonic pulse sequence may refer to at least one ultrasonic pulse associated with a moment or two or more ultrasonic pulses associated with two or more moments. In some embodiments, the background signal detection step (step 402) and the container detection step (step 404) may be determined at a lower sampling rate (e.g., about 0.5 Hz to about 5 Hz). Once container 118 is detected, the sampling rate can be increased (e.g., from about 10 Hz to about 30 Hz).

[0086] At step 406, the sensing system 202 can determine the surface based on the reflected pulse sequence (see reference). Figure 5 The surface determination process (described) identifies the edges 122 and bottom 120 of container 118. Generally, the surface determination process removes background noise and further processes the raw ultrasonic reflected pulses to provide enhanced identification of immovable and / or movable surfaces. In some embodiments, the sensing system 202 may further determine (e.g., based on reflected ultrasonic pulses and / or another sensor) whether container 118 is correctly positioned in the dispensing area 110 so that liquid 124 can be fully dispensed into the container (e.g., no portion is dispensed onto the dispensing housing 102). In some embodiments, the sensing system 202 may prompt the user via an optional display unit 228 (and / or an optional user interface 230) to reposition container 118 in the dispensing area 110. In some embodiments, steps 404 and 406 may be performed simultaneously.

[0087] See Figure 8B The diagram illustrates a time-varying sequence of reflected pulses from an empty container 118 positioned within the distribution area 110. When the empty container 118 is placed below the ultrasonic transducer 112, the time-varying peaks (i.e., the larger amplitude portions) of the reflected signal represent the bottom 804 and top edge 806 of the empty container 118. In some embodiments, the range / distance (to the ultrasonic transducer 112) can be determined from the time-of-flight (TOF) of the reflected signal, as described above.

[0088] At optional step 408, sensing system 202 can determine whether the (empty) container 118 is stable (e.g., does not involve significant movement). For example, sensing system 202 can determine whether the reflected ultrasonic signal (in response to the surface determination process) includes any time-varying variance. If the variance is less than a predetermined threshold, sensing system 202 can determine that container 118 is stable.

[0089] When it is determined at optional step 410 that container 118 is unstable (e.g., variance is greater than or equal to a predetermined threshold), step 410 can proceed to optional step 408. Optional steps 408 and 410 can be repeated until container 118 is determined to be stable. In some embodiments, after a predetermined period of time, sensing system 202 may determine to prevent any dispensing operation if the stability of container 118 cannot be obtained. In some embodiments, sensing system 202 may prompt the user via optional display unit 228 (and / or optional user interface 230) to place container 118 on dispenser housing 102, and / or require the user to try different containers and restart the dispensing process.

[0090] When it is determined at optional step 410 that container 118 is stable (e.g., the variance is less than a predetermined threshold), optional step 410 can proceed to step 412.

[0091] At step 412, the liquid dispensing system 204 can begin dispensing liquid 124 via dispenser nozzle 114. For example, in response to step 406 (and in some embodiments, alternatively steps 408 and 410), the sensing system 202 can generate a start command and send it to the dispenser controller 224 via interface 220. In response to the start command, the dispenser controller 224 can cause the dispenser nozzle 114 to begin dispensing liquid 124 from the liquid source 226. In this way, the system 200 can automatically begin filling container 118 with liquid 124.

[0092] At step 414, the sensing system 202 can determine the process based on the surface ( Figure 5 The liquid level 126 in container 118 is determined by processing a sequence of reflected ultrasonic pulses. In some embodiments, the sensing system 202 can determine the liquid level 126 in container 118 by comparing the bottom position of bottom 120, the edge position of edge 122, and the liquid level position of liquid level 126 (see...). Figure 1 The fill level of container 118 is determined. In some embodiments, the fill level may be displayed as feedback to the user via optional display unit 228 and / or optional user interface 230. In some embodiments, steps 412 and 414 may be performed simultaneously.

[0093] At step 416, the sensing system 202 can repeatedly monitor the liquid level 126 by repeatedly determining the liquid level using a time-varying sequence of reflected ultrasonic pulses (step 414) while the liquid 124 is being dispensed.

[0094] At step 418, the sensing system 202 can compare the detected liquid level (step 416) with at least one threshold. In some embodiments, the predetermined threshold may include, but is not limited to, a predetermined distance from the edge location, the edge location itself, a predetermined percentage of the fill level, etc. In some embodiments, the sensing system 202 can determine the distance D1 between the liquid level location and the edge location. Figure 1 The distance D1 is used to determine when to stop filling container 118. In some embodiments, the sensing system 202 may use both edge position and bottom position, as well as liquid level position. Figure 1 Together, we determine when to stop filling container 118.

[0095] When it is determined at step 418 that the liquid level 126 is less than or equal to a predetermined threshold, step 418 proceeds to step 416, and steps 416 and 418 can be repeated.

[0096] When it is determined at step 418 that the liquid level 126 is greater than a predetermined threshold, step 418 can proceed to step 420 and stop the dispensing of liquid 124. For example, the sensing system 202 can generate a stop command and send it to the dispenser controller 224 via interface 220. In response to the stop command, the dispenser controller 224 can prevent liquid 124 from being dispensed from the dispenser nozzle 114 from the liquid source 226. In this way, once the predetermined filling threshold is reached, the system 200 can automatically stop filling the container 118 with liquid 124.

[0097] Therefore, in step 420, system 200 can automatically stop dispensing when a predetermined threshold (e.g., an indicated / preset fill level) is reached. In some embodiments, sensing system 202 can also stop the dispensing action (of liquid dispensing system 204) when sensing system 202 determines that container 118 has been removed, not properly positioned, or held during any of steps 412-416. As shown in method 400, after detecting container 118 and determining the edge 122 and bottom 120 of container 118 (steps 404 and 406), system 200 can begin automatically filling container 118. In some embodiments, sensing system 202 can also detect whether container 118 is positioned or held, and can cause liquid dispensing system 204 to adjust the dispensing accordingly (in step 412) (e.g., adjust the filling speed, adjust the temperature, etc.).

[0098] refer to Figure 8C and Figure 8D The image shows a time-varying sequence of reflected pulses in a container being filled with liquid. Figure 8C Displaying amplitude-processed ultrasound signals, while Figure 8D Displaying ultrasound signals after variance processing. For example... Figure 8C As best shown, the container is initially empty. The amplitude-processed signal indicates bottom reflection 808 and edge reflection 810, which indicate the corresponding bottom and edge (non-movable surfaces) of the empty container. This can be seen in... Figure 8C As can be seen, the edge reflection 810 does not change significantly over time (provided the container does not move).

[0099] As the liquid is dispensed, a movable surface is created. As indicated by the liquid level reflection 812, the distance from the liquid level (from the ultrasonic transducer 112) also changes with the liquid level. Therefore, over time, as the liquid is dispensed, the liquid level reflection 812 moves from a level near the bottom of the container (bottom reflection 808) towards the edge of the container (edge ​​reflection 810).

[0100] In some embodiments, the range of the changing liquid level can be determined (from liquid level reflection 812), from Figure 8CThe changing liquid level is determined from the intensity map after amplitude processing. For example, the filling level 814 can be determined between the liquid level and the bottom of the container based on the liquid level reflection 812 (at a specific moment) and the bottom reflection 808 (before filling the container).

[0101] In some embodiments, such as Figure 8D As shown, the variance of the (amplitude-processed) signal can be used to more clearly define the changing liquid level, which can help detect the changing liquid level. Figure 8D The variance-enhanced detection of level reflection 812 shown in the figure significantly minimizes bottom reflection 808 and edge reflection 810 (whose positions do not change substantially over time).

[0102] In some embodiments, it is possible to use Figure 8C The amplitude-processed signal shown is used to detect the edges and bottom of the container using background subtraction techniques. Since the container edges and bottom do not change position, an averaging method can be used to measure the position at multiple moments, from bottom reflection 808 and edge reflection 810. Even if the container is handheld, determining the average value allows for the detection of the container's bottom and edges. In some embodiments, the following methods can be used... Figure 8D The variance-processed signal shown is used to detect and monitor changing liquid levels.

[0103] refer to Figure 5 A flowchart illustrating an exemplary method 500 for determining the distance to a surface (e.g., a movable and / or immovable surface) via ultrasonic measurement is shown. Method 500 refers to... Figures 9A-9C Description. In particular, Figure 9A This is an exemplary graph showing the amplitude of the raw ultrasonic reflected signal as a function of distance for empty containers and empty dispenser areas; Figure 9B It is used for Figure 9A An exemplary graph showing the amplitude of the ultrasonic reflected signal after filtering amplitude processing and filtering variance processing for an empty container as a function of distance; Figure 9C It is used when a container is filled with liquid at a specific moment. Figure 9A and 9B An exemplary graph showing the functional relationship between the amplitude and distance of the filtered amplitude-processed and filtered variance-processed ultrasonic reflected signals. Figures 9A-9C In this context, the resulting signal is shown as the amplitude as a function of distance (millimeters) (for low sideband (LSB) modulation).

[0104] At step 502, the ultrasonic pulse sequence may be transmitted by ultrasonic transducer 112. For example, transceiver circuit 206 may cause ultrasonic transducer 112 to transmit ultrasonic pulse 116 sequence to distribution area 110. At step 504, the ultrasonic pulse sequence reflected by at least one surface (movable and / or immovable) may be received. For example, transceiver circuit 206 may cause ultrasonic transducer 112 to receive ultrasonic pulse 116 sequence reflected from immovable surface (e.g., bottom surface 120 of container 118, edge 122 of container 118) and / or movable surface (e.g., liquid level 126 of liquid 124 in container 118). In some embodiments, the received reflected pulse sequence (step 504) may be stored in memory 218.

[0105] At step 506, at least one background signal can be removed from the (received) reflected pulse sequence (step 504) (determined in step 402). For example, the processor 216 of the sensing system 202 can use one or more background subtraction techniques to remove the background signal from the reflected pulse sequence. In a non-limiting embodiment, a loop drop can be subtracted from the current signal in the in-phase and quadrature (IQ) domain. The resulting signal can be passed to an amplitude filter to form a filtered amplitude signal. For example, IQ data (e.g., in...) Figure 6 The background signal captured at step 610 in the process can be stored (e.g., in...). Figure 2 (In memory 218). Stored IQ data (background signal) can be subtracted from the current signal in the IQ domain, where the in-phase (I) component and the quadrature (Q) component are processed separately. In this way, the I component of the background signal can be subtracted from the I component of the current signal, and the Q component of the background signal can be subtracted from the Q component of the current signal. In some embodiments, background subtraction can be performed in the amplitude domain, where the amplitude of the background signal can be subtracted from the amplitude of the current signal.

[0106] At step 508, an output signal sequence can be generated based on amplitude and / or variance processing of the (noise-processed) reflected signal sequence. In some embodiments, amplitude / variance processing may include applying one or more filters to the (noise-processed) reflected signal sequence (determined in step 506). An embodiment of calculating the filtered amplitude and variance is described below.

[0107] At step 510, at least one surface can be identified from one or more output signals in the output signal sequence. Generally, each output signal (with reflections from at least one surface) may include one or more peaks indicating the surface. The surface can be identified from the peaks in the output signals. In some embodiments, peaks in the amplitude-processed (in some embodiments, filtered) output signals can be identified, indicating the edges and bottom of the container. Peaks in the variance-processed (in some embodiments, filtered) output signals can be identified, indicating the changing liquid level in the container. At step 512, the distance (e.g., range) of the identified surface can be determined from the corresponding peaks in the output signals based on the (TOF) value to range value conversion (as described above).

[0108] Figure 9A This displays the raw ultrasonic reflection signals for the empty distribution area 110 (background signal) and the empty container within distribution area 110. Figure 9A In the diagram, signal 902 represents the original amplitude of at least one reflected ultrasound pulse (at a specific moment); signal 904 represents the measured ring drop signal (background signal). Figure 9A An example illustrating typical raw received data when the container is positioned below the ultrasonic transducer 112.

[0109] Figure 9A Also shown is a drop indicator 910, a peak 914 indicating reflection from the edge 122 of container 118 (referred to herein as edge peak 914), and a peak 916 indicating reflection from the bottom 120 of container 118 (referred to herein as bottom peak 916).

[0110] Figure 9B Showing on Figure 9A The data shown is filtered and used for the amplitude and variance (reflected ultrasonic pulse) data of container 118. Figure 9B In the diagram, signal 918 represents the filtered amplitude, and signal 920 represents the filtered variance. Figure 9B It also displays the peak value 922 representing the ring drop that is essentially canceled, the signal portion 924 representing the variance of the edge, the detected edge distance 926, and the detected bottom distance 928.

[0111] like Figure 9B As shown, the filtered amplitude signal 918 produces a strong peak indicating edge 122. In contrast, signal portion 924 (associated with edge 122) produces a small edge variance, and the position of indicating edge 122 does not change significantly. Therefore, due to the large peak generated by the changing liquid level (such as... Figure 9CAs shown, the filtered variance signal 920 can be used to detect and monitor changing liquid levels (as indicated by detected liquid levels) while minimizing the possibility of misidentifying edge peaks 914 as liquid levels. This is because the edge portion 924 of edge 122 is significantly reduced in the variance signal 920 compared to the amplitude signal 918.

[0112] Figure 9C This displays filtered amplitude and variance (reflected ultrasonic pulse) data used for container 118 during liquid dispensing. Figure 9C In the diagram, signal 918 represents the filtered amplitude, and signal 920 represents the filtered variance. Figure 9C It also shows the detected edge distance of 926 and the detected liquid level distance of 932. Figure 9C The large variance (signal 920) caused by the moving liquid is shown (indicated by the large peak 930). As liquid 124 flows into container 118, the large variance in the original amplitude data can be observed. Signal 920 represents the variance of the amplitude data (signal 918) at each distance point. Liquid level distance 932 can be used as the leading edge of the large variance pulse 930.

[0113] The following provides a non-limiting embodiment for determining the filtered amplitude and variance signal (an exemplary output signal that may be determined at step 508).

[0114] In some embodiments, the filtered amplitude signal (“filt_mag”) can be determined as follows. The filtered amplitude signal can first be initialized using an initial amplitude value (“mag” or zero). The amplitude signal can be applied to a filter (an embodiment of which is shown in the pseudocode below). A scaling factor (“alpha”) can be selected for the filter, which can be a value between 0 and 1. The filter can be applied to IQ domain sensor data (one filter for the in-phase (I) component and one filter for the quadrature (Q) component) or to amplitude data, where the amplitude can be determined using sqrt(I^2 + Q^2), where “sqrt” denotes the square root function. When the filter is applied to IQ domain sensor data, the amplitude can be determined after the filtering operation.

[0115] The following pseudocode represents an exemplary determination of the filtered amplitude signal:

[0116] def update_filt_mag(mag,filt_mag,alpha):

[0117] for(x,y)in(mag,filt_mag):

[0118] y = alpha*x + (1 – alpha)*y.

[0119] The filtered variance signal (“filt_var”) can be determined as follows. Similar to the filtered amplitude signal, the filtered variance signal can first be appropriately initialized (e.g., initialized to zero). The scaling factor (“alpha”) can represent a value from 0 to 1, which controls the amount of filtering of the amplitude data. The scaling factor (“alpha_var”) represents a value between 0 and 1, which controls the amount of filtering of the variance signal. The variance signal filter can determine the squared difference (“sq-diff”) between the current amplitude and the time-averaged amplitude.

[0120] The following pseudocode represents an exemplary determination of the filtered variance signal:

[0121] update_filt_mag(mag,filt_mag,alpha)

[0122] sq_diff = mag^2 - filt_mag^2 # Subtract element by element

[0123] update_filt_mag(sq_diff,filt_var,alpha_var).

[0124] The filtered amplitude signal and the filtered variance signal can then be compared to one or more thresholds to determine the edge and level. For example, the pseudocode for the filtered amplitude signal may include additional pseudocode for update_rim_signal (e.g., to determine the edge from the filtered amplitude based on at least one threshold). The pseudocode for the filtered variance signal may include additional pseudocode for liquid_signal (e.g., to determine the level from the filtered variance).

[0125] Next reference Figure 6 The diagram illustrates a flowchart of an exemplary method 600 for calibrating a background signal according to one aspect of this disclosure. In some embodiments, the background signal may be sampled periodically to ensure its accuracy. For example, the background signal may change over time due to factors such as temperature, power cycling, etc.

[0126] As part of calibration, it is desirable to sample the background signal when no container is placed within the field of view. The background signal may affect the ability to detect container edges and liquid levels near the ultrasonic transducer 112. The area near the ultrasonic transducer 112 is referred to as the "ringdown region." For proper calibration, it is desirable to detect a container outside the ringdown region at least once. This may occur at fixed intervals during sensor operation. After the initial calibration, calibration can be performed again after "any" container has been detected and removed.

[0127] At step 602, the container can be detected, having an edge outside the descending region. At step 604, the container can be removed. At step 606, the sensing system 202 can determine whether a predetermined time (e.g., approximately 5 seconds) has elapsed since the container was removed (referred to herein as the condition). At step 608, it is determined whether the condition (step 606) has been met. If the condition is not met, step 608 can proceed to step 602.

[0128] When the condition is met, step 608 can proceed to step 610. At step 610, the current signal can be captured via the ultrasonic transducer 112, and the current signal can be defined as the background signal. At step 612, it is determined whether the container is detected within the ring-drop region.

[0129] When the sensor system 202 determines that the container has been detected, step 612 proceeds to step 614. At step 614, the container can be removed, and step 614 can proceed to step 616. At step 616, step 606 can be repeated, and step 616 can proceed to step 618.

[0130] When the sensing system 202 determines that the container has not been detected, step 612 can proceed to step 616. At step 616, step 606 can be repeated, and step 616 can proceed to step 618.

[0131] When it is determined at step 618 that the condition (in step 606) is met, step 618 can proceed to step 610, and the new signal can be captured as a background signal. When it is determined at step 618 that the condition is not met, step 618 can proceed to step 612. In this way, the background signal can be periodically determined and updated to reflect the latest operating conditions for the ultrasonic transducer 112.

[0132] Next reference Figure 7A and Figure 7B This illustrates an exemplary process for controlling the dispensing of liquid into a container (e.g., a cup). Specifically, Figure 7AThis is a state diagram 700 illustrating an exemplary state for controlling the dispensing of liquid into a container (e.g., a cup); Figure 7B This is a table displaying exemplary events associated with state diagram 700. In some embodiments, state diagram 700 may be implemented by processor 216. Figure 7B The table shown can be stored in memory 218. In some embodiments, state diagram 700 can be used by processor 216 to generate instructions for allocator controller 224. Although Figure 7A and Figure 7B The illustration shows the control of dispensing into the cup, but it is understood that the cup represents a non-limiting embodiment of the container.

[0133] exist Figure 7B In the table shown, events 710-716 can be determined by processing one or more reflected ultrasound signals to generate filtered amplitude and variance signals (see the “Based on” column), also referred to throughout this disclosure as the output signal. The conditions used to trigger one of events 710-716 may depend on various thresholds (ADs) and specific output signals (e.g., filtered amplitude signal, filtered variance signal). State diagram 700 assumes that the reflected ultrasound pulse sequence is measured, processed, and filtered at various states 702-708 (as in...). Figure 5 Method 500 is shown.

[0134] At state 702 (no cup, dispensing = 0), processor 216 can determine that no cup (e.g., in the embodiment of container 118) is located within dispensing area 110, for example, based on the characteristics of the received reflected ultrasonic pulse 116. While in state 702, processor 216 can recognize that event 710 (edge ​​detected) has occurred. For example, an edge can be detected from the peak of the filtered amplitude signal when the amplitude (of the peak) is greater than a predetermined threshold A. When event 710 is determined to have occurred, state 702 can proceed to state 704.

[0135] At state 704 (edge ​​detection, assignment = 0), processor 216 can determine that one of events, 712 (edge ​​stable) and 714 (no edge), has occurred. For example, event 712 can be determined to have occurred when the filtered variance signal at the edge distance (determined in event 710) is less than a predetermined threshold B. Event 714 can be determined to have occurred when the filtered amplitude signal is less than a predetermined threshold C (e.g., at the edge distance determined in event 710).

[0136] When determination event 712 occurs, state 704 can advance to state 706. When determination event 714 occurs, state 704 can advance to state 702 (no cup, allocation = 0).

[0137] At state 706 (cup ready, dispensing = 1), processor 216 can instruct dispenser controller 224 to begin dispensing liquid 124 (e.g., dispensing = 1). At state 706, processor 216 can also determine whether event 716 or event 714 has occurred. For example, event 716 can be determined to have occurred when the fill level is greater than a predetermined threshold D. The fill level can be determined based on (filtered) variance. For example, (filtered) variance can be used to determine and monitor the distance from the liquid level (e.g., range). The distance from the edge (e.g., range) can be determined from (filtered) amplitude (e.g., in event 710). The distance between the edge and the liquid level (e.g., the range from the liquid level and the range from the edge) can be compared with the threshold D to determine when to stop filling the cup.

[0138] When determination event 714 occurs, state 706 progresses to state 702. When determination event 716 occurs, state 706 progresses to state 708.

[0139] At state 708 (cup full, dispensing = 0), processor 216 can instruct dispenser controller 224 to stop dispensing liquid 124 (e.g., dispensing = 0). At state 706, processor 216 can also determine whether event 714 has occurred. When event 714 occurs, state 708 can proceed to state 702. In this way, dispensing for the container is completed, and system 200 can wait for another container to be positioned for contactless automatic dispensing.

[0140] While this disclosure has discussed certain embodiments, it should be noted that this disclosure is not limited thereto. These embodiments are explained by way of example, but many modifications, variations, and other embodiments may be adopted, which are still within the scope of this disclosure.

Claims

1. A system for monitoring a movable surface, the system comprising: Time-of-flight sensor; The circuitry coupled to the time-of-flight sensor is configured to cause the time-of-flight sensor to transmit a sequence of pulses and receive a sequence of reflected signals in response to the transmitted pulse sequence, each reflected signal in the sequence of reflected signals including at least one first reflection and at least one second reflection, the at least one first reflection being associated with at least one immovable surface and the at least one second reflection being associated with a movable surface. as well as A digital controller is configured to, for each reflected signal in a sequence of reflected signals, identify at least one first pulse indicating the at least one immovable surface and at least one second pulse indicating a movable surface, and determine the distance of the movable surface relative to the at least one immovable surface based on the identified at least one first pulse and the identified at least one second pulse; Its features The digital controller is configured as follows: Determine the amplitude and variance of a single reflected signal in the reflected signal sequence; At least one predefined filter is applied to the determined amplitude and variance to generate filtered amplitude and filtered variance; The at least one first pulse indicating the at least one immovable surface is identified based on the filtered amplitude of a corresponding reflected signal in the reflected signal sequence; The at least one second pulse indicating a movable surface is identified based on the filtered variance of a corresponding reflected signal in the reflected signal sequence; and The distance of the movable surface relative to the at least one immovable surface is determined based on at least one first pulse and at least one second pulse identified.

2. The system of claim 1, wherein the distance of the movable surface relative to the at least one immovable surface is determined based on at least one first flight time indicated by the at least one first pulse and a second flight time indicated by the at least one second pulse.

3. The system of claim 1, wherein the digital controller is configured to determine the stability of the at least one immovable surface based on the filtered variance of a corresponding reflected signal in the sequence of reflected signals.

4. The system of claim 1, wherein the system is configured to determine a liquid level inside a container, a movable surface including the liquid level, and the at least one immovable surface including one or more of an edge and a bottom of the container; and When the container is not present within the predetermined detection area, a background signal is determined via a time-of-flight sensor. This background signal includes a ring fall component, and... The digital controller is configured to subtract the background signal from the reflected signal sequence to minimize the ring drop component in the reflected signal sequence.

5. The system of claim 4, wherein the system is configured to periodically determine a background signal.

6. The system of claim 4, wherein the system is configured to determine one or more of the presence of a background signal and a container at a first sampling rate, and to utilize a second sampling rate for the received sequence of reflected signals, wherein the first sampling rate is lower than the second sampling rate.

7. An apparatus for dispensing liquid in a container, the apparatus comprising: A dispenser configured to dispense liquid into containers; as well as A system for monitoring movable surfaces as described in any one of claims 1 to 6; in The at least one first reflection is associated with a portion of the container, and the at least one second reflection is associated with the level of liquid dispensed into the container, the portion of the container including at least one of an edge and a bottom surface; as well as The digital controller is configured to monitor changes in liquid level with a sequence of reflected signals based on a determined distance in order to control the distribution of liquid via the dispenser.

8. The apparatus of claim 7, wherein prior to transmitting the pulse sequence, the system is configured to detect the presence of a container within a predetermined detection area via a time-of-flight sensor, and in response to detecting the container, cause the dispenser to begin dispensing liquid into the container; and The digital controller is configured to monitor the liquid level based on a determined distance and to stop dispensing liquid when the determined distance is within a predetermined threshold relative to the edge of the container.

9. The apparatus according to claim 7 or 8, wherein, The at least one time-of-flight sensor includes at least one of an ultrasonic sensor, a radar sensor, and an optical sensor.

10. A method for monitoring a movable surface, the method comprising: The time-of-flight sensor is made to emit a pulse sequence via a circuit coupled to it; The circuit receives a sequence of reflected signals in response to a sequence of transmitted pulses, each reflected signal in the sequence including at least one first reflection and at least one second reflection, the at least one first reflection being associated with at least one immovable surface and the at least one second reflection being associated with a movable surface; For each reflected signal in the reflected signal sequence, at least one first pulse indicating the at least one immovable surface and at least one second pulse indicating the movable surface are identified, and the distance of the movable surface relative to the at least one immovable surface is determined based on the identified at least one first pulse and at least one second pulse. Its features are: The method includes: The amplitude and variance of a single reflected signal in the reflected signal sequence are determined by a digital controller. Apply at least one predefined filter to the determined amplitude and variance to generate filtered amplitude and filtered variance; The at least one first pulse indicating the at least one immovable surface is identified by a digital controller based on the filtered amplitude of a corresponding reflected signal in the sequence of reflected signals; and The at least one second pulse indicating a movable surface is identified by a digital controller based on the filtered variance of a corresponding reflected signal in the sequence of reflected signals. The distance between the movable surface and the at least one immovable surface is determined by a digital controller based on at least one first pulse and at least one second pulse identified.

11. The method of claim 10, wherein the distance of the movable surface relative to the at least one immovable surface is determined based on at least one first flight time indicated by the at least one first pulse and a second flight time indicated by the at least one second pulse.

12. The method of claim 10, wherein identifying the at least one first pulse and the at least one second pulse further comprises: The stability of the at least one immovable surface is determined based on the filtered variance of a corresponding reflected signal in the reflected signal sequence.

13. The method of claim 10, wherein the movable surface includes a liquid level, the at least one immovable surface includes one or more of a container edge and a container bottom, the container is configured to contain liquid, and determining the distance of the movable surface relative to the at least one immovable surface includes determining the liquid level inside the container; and The method further includes: When the container is not present within the predetermined detection area, a background signal is determined via a time-of-flight sensor. This background signal includes a ring fall component, and... The background signal is subtracted from the reflected signal sequence via a digital controller to minimize the ring drop component in the reflected signal sequence.

14. The method of claim 13, further comprising periodically determining a background signal; and optionally... Determine the presence of one or more of the background signal and the container using a first sampling rate; and The received reflected signal sequence is sampled at a second sampling rate, where the first sampling rate is lower than the second sampling rate.

15. The method of claim 10, further comprising, before transmitting the pulse sequence: The presence of a container within a predetermined detection area is detected using a time-of-flight sensor; In response to the detection of a container, the dispenser begins dispensing liquid into the container; and optionally... Based on a defined distance, the liquid level is monitored via a digital controller; and The dispenser stops dispensing liquid when the determined distance relative to the edge of the container is within a predetermined threshold.

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