Acoustic imaging system with rotational speed detection

Abstract

An acoustic imaging device including an acoustic sensor array is configured to receive information indicating a rotational speed of a mechanical device, and based on the rotational speed, select one or more frequencies at which to analyze acoustic data representing an acoustic signal from the mechanical device. In some cases, the acoustic imaging device is configured to capture the acoustic data at the one or more frequencies from an environment including the mechanical device. The acoustic data may be captured within one or more frequency bands associated with historical failure modes of the mechanical device. The acoustic imaging device may automatically determine a severity of degradation of the mechanical device based on a combination of the rotational speed and the acoustic data. Image data depicting the mechanical device may be overlaid with information derived from the acoustic data in at least a portion of the one or more frequencies.

Description

ACOUSTIC IMAGING SYSTEM WITH ROTATIONAL SPEED DETECTIONBACKGROUND

[0001] Mechanical systems, such as rotating components (bearings, pulleys, and the like) may emit acoustic signals that change over time as the systems degrade. Mechanical system degradation and failure may be detected through the use of acoustic imaging, for example by capturing acoustic signature data associated with a mechanical device at two or more different times, and comparing those acoustic signatures to detect changes indicative of degradation.

[0002] Current attempts to monitor mechanical system degradation or failure using acoustic analysis typically involve monitoring a decibel reading at a single, predetermined frequency, e.g., 30 Hz. However, the acoustic response of mechanical system degradation is often not limited to or reliably detectable at a single frequency.

[0003] Mechanical systems may operate at different speeds or rotational rates - e.g., in a low- speed range of, e.g., 60 to 300 RPM or lower, or at a higher speed, such as above 300 RPM. Different mechanical systems operating at different rotational speeds may emit noise (audible and inaudible to human hearing) at different frequencies. That noise may be “normal” noise, or may be indicative of degradation of the mechanical system due to, e.g., loss of lubrication, degradation of components, such as bearings, and the like. Noise may be generated at different frequencies or across broad frequency spans, based, in part, on the operating speeds of the respective mechanical systems. As such, it can be difficult to determine an appropriate frequency, or frequencies, at which to monitor acoustic signals emitted from such systems. Furthermore, it can sometimes be computationally complex and / or prohibitive to monitor acoustic signals across an entire acoustic range, where large portions of a given frequency range may have uninteresting or irrelevant acoustic response. Additionally, due to the often complex nature of broad-frequency acoustic emissions from these mechanical systems, analysis of performance can be challenging from a perspective of both time and computational effort.SUMMARY

[0004] In general, the present disclosure relates to an acoustic imaging system with rotational speed detection. The devices, systems, and methods described herein utilize automatic rotational speed detection systems as part of an acoustic imaging process. In some examples, an acoustic imaging system with rotational speed detection is disclosed. Rotational speed may be detected in conjunction with capture of both image data and acoustic data regarding a mechanical system under analysis. Specific acoustic frequencies are selected based on a detected or receivedrotational speed. A user interface may display the detected rotational speed and an overlay of acoustic signal strength within the selected acoustic frequencies.

[0005] In some instances, specific frequency ranges are selected based on the automatically detected rotational speed. Such selection of analysis frequencies simplifies user operation of an acoustic imaging system, and reduces computational analysis required by selecting relevant portions of an acoustic frequency range for performing analysis.

[0006] In accordance with a first aspect, an acoustic imaging device includes an acoustic sensor array, a camera system, a display, a processing system, and a memory. The processing system is communicatively connected to the acoustic sensor array, the camera system, and the display, and the memory is communicatively connected to the processing system. The memory stores instructions which, when executed by the processing system, cause the acoustic imaging device to: receive information indicating a rotational speed of mechanical device; in response to the rotational speed, select one or more frequencies at which to analyze acoustic data emitted from the mechanical device; and capture, at the one or more frequencies, acoustic data from an environment including the mechanical device via the acoustic sensor array.

[0007] According to a second aspect, an acoustic imaging device includes an acoustic sensor array, a camera system, a display, a processing system, and a memory. The processing system is communicatively connected to the acoustic sensor array, the display, and the camera system, and the memory is communicatively connected to the processing system. The memory stores instructions which, when executed by the processing system, cause the acoustic imaging device to: receive information indicating a rotational speed of a mechanical device; receive acoustic data captured at the acoustic sensor array, the acoustic data representative of acoustic signals emitted by the mechanical device; and perform at least one of (1) automatically determining one or more predetermined frequencies at which to analyze the acoustic data based on the rotational speed, or (2) automatically determining a severity of degradation of the mechanical system based on a combination of the rotational speed and the acoustic data.

[0008] According to a third aspect, a method of performing acoustic imaging on a mechanical system is disclosed. The method includes receiving, at an acoustic imaging device, information indicating a rotational speed of a mechanical device. The method also includes, in response to the rotational speed, selecting, by the acoustic imaging device, one or more frequencies at which to analyze acoustic data emitted from the mechanical device. The method further includes capturing, at the acoustic imaging device, image data depicting the mechanical device, and capturing, via an acoustic sensor array of the acoustic imaging device, acoustic data at the one or more frequencies from an environment including the mechanical device. The method further includes displaying, on a display of the acoustic imaging device, a user interface including an image of a field of viewof the camera system including an overlay of a detected acoustic signa strength obtained from the acoustic sensor array for at least a portion of the one or more frequencies selected in response to the rotational speed.

[0009] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Non-limiting and non-exhaustive examples are described with reference to the following figures:

[0011] Fig. 1 is a block diagram illustrating components of an example acoustic imaging system in which aspects of the present disclosure may be implemented.

[0012] Fig. 2 is a schematic front plan view of an acoustic imaging device on which example aspects of the present disclosure may be implemented.

[0013] Fig. 3 is a schematic rear plan view of the acoustic imaging device of Fig. 2.

[0014] Fig. 4 is a schematic plan view of an acoustic imaging sensor array that may be integrated into an acoustic imaging device, according to example aspects of the present disclosure.

[0015] Fig. 5 is a schematic rear plan view of an alternative embodiment of the acoustic imaging device of Fig. 2.

[0016] Fig. 6 is a schematic rear plan view of a further alternative embodiment of the acoustic imaging device of Fig. 2.

[0017] Fig. 7 is a flowchart of an example method of performing acoustic imaging on a mechanical system based on rotational speed of the mechanical system.

[0018] Fig. 8A is a sub-method for identifying one or more frequencies for analysis based on rotational speed, according to an example embodiment.

[0019] Fig. 8B is a second sub-method for identifying one or more frequencies for analysis based on rotational speed, according to an example embodiment.

[0020] Fig. 8C is a third sub-method for identifying one or more frequencies for analysis based on rotational speed, according to an example embodiment.

[0021] Fig. 9A illustrates a lookup table useable to identify frequencies for analysis based on rotational speed, according to example embodiments.

[0022] Fig. 9B illustrates an analysis frequency selection model useable to identify frequencies for analysis based on rotational speed, according to example embodiments.

[0023] Fig. 10 is an example user interface illustrating selection of a rotational speed input mechanism for use in acoustic imaging of mechanical equipment, according to example embodiments.

[0024] Fig. 11 is an example user interface depicting detected rotational speed and acoustic frequency analysis at a selected frequency range, in accordance with example embodiments.

[0025] Fig. 12 is an example user interface depicted receipt of user-entered rotational speed, in accordance with example embodiments.

[0026] Fig. 13 is an example user interface for switching among rotational speed frequency multiples to validate a detected rotational speed, in accordance with example embodiments.

[0027] Fig. 14 is a flowchart of an example generalized method of performing acoustic imaging on a mechanical system based on rotational speed of the mechanical system.

[0028] Fig. 15 is a flowchart of an example method of determining degradation of a mechanical system using a severity analysis based on rotational speed of the mechanical system, in accordance with example embodiments.DETAILED DESCRIPTION

[0029] As briefly described above, embodiments of the present disclosure relate to an acoustic imaging system with rotational speed detection. The devices, systems, and methods described herein utilize rotational speed detection systems as part of an acoustic imaging process. In some examples, an acoustic imaging system with automatic rotational speed detection is disclosed. Rotational speed may be detected in conjunction with capture of both image data and acoustic data regarding a mechanical system under analysis. Specific acoustic frequencies may be selected based on a detected or received rotational speed. A user interface may display the detected rotational speed and an overlay of acoustic signal strength within the selected acoustic frequencies. In some instances, a severity of degradation may be informed by the detected rotational speed.

[0030] In some instances, a rotational speed sensor may be integrated into an acoustic imaging device. In some cases, a laser tachometer, stroboscope, or image frame analysis may be used to determine rotational speed of mechanical equipment, such as a mechanical device. Based on the determined rotational speed, acoustic analysis that is performed may be improved. For example, a set of analysis frequencies may be selected, at least in part, based on the determined rotational speed. Additionally, or alternatively, severity of degradation and / or failure mode of mechanical equipment may be better determined from acoustic analysis if the rotational speed of the equipment being analyzed is known.

[0031] In some examples, rotational speed may be obtained through alternate means. For example, rotational speed may be determined by image analysis, and optionally optical character recognition, of displays associated with mechanical equipment.

[0032] In response to receipt of rotational speed information, acoustic imaging analysis may be affected. As noted above, different frequency ranges may be selected for analysis depending on the rotational speed of the mechanical device. This is because it may be computationally intensive and / or require significant time to perform acoustic analysis across an entire practical acoustic frequency range. Different devices operating at different rotational speeds will respond differently, and exhibit different failure characteristics, at different frequencies, and selection of frequencies that correspond to operating rotational speeds improves the efficiency of such analysis. In still further examples, acoustic signals may only be captured within a selected frequency or frequency range; in such instances, similar computational efficiencies are achieved by avoiding the requirement of analysis across an entire acoustic frequency range. Further, time and / or resources that would be required to capture acoustic signals across the entire frequency range are also reduced.

[0033] In some instances, capture of rotational speed can occur prior to, or concurrently with, capture of image and acoustic data by an acoustic imaging device. In other instances, rotational speed may be supplied via a rotational speed sensor or other means prior to capture of the image and acoustic data, thereby allowing analysis frequencies to be selected prior to capture of acoustic data. In still further examples, rotational speed information may be appended to captured acoustic and image data, and may be used in post-processing analysis of that data to determine, for example, severity of degradation based on intensity of the acoustic signal and relationship between that intensity and the rotational speed.

[0034] When used in an acoustic imaging device, a user interface may be provided to allow convenient entry and validation of rotational speed. For example, manual input of a rotational speed may be allowed (e.g., to override an incorrectly detected speed or append a rotational speed to previous analysis). User interface features are also provided, in some circumstances, for switching among speed multipliers to validate correctness of a detected speed. Such features provide further advantages in terms of speed of analysis and user convenience.I. Operating Environment and Example Acoustic Imaging Systems

[0035] Referring first to Figs. 1-4, example acoustic imaging systems in which the user interfaces and methods of use and operation may be performed are described. The systems described herein should be considered exemplary, in that the user interfaces may be presented ona wide variety of types of systems and in various contexts, as is apparent from the details of those interfaces themselves.

[0036] Referring initially to Fig. 1, an example acoustic imaging system 100 is depicted. The acoustic imaging system may include, in the example shown, an acoustic imaging device 102, optionally communicatively connected to one or more remote computing systems, such as remote system 10 and one or more rotational speed sensor systems 180.

[0037] The acoustic imaging device 102 may be, in various embodiments, a handheld device, a robotic or self-propelled device (e.g., either ground-based or airborne, as in the case of a drone), or a stationary device positioned to receive acoustic signals. In general terms, an acoustic imaging device, also referred to herein as an acoustic camera or acoustic imaging system, visualizes sound waves and creates images or maps of sound fields in a given area. An acoustic imaging device is designed to detect and display sound sources and their distribution, for example in real time. In the example shown, the acoustic imaging device 102 includes a processing system 110 communicatively connected to a memory 112, as well as to an acoustic sensor array 120, a camera system 125, a display 130, input devices 132, a power subsystem 140, and a communication interface 150. As illustrated, the acoustic imaging device 102 may also include, in some examples, a rotational speed sensor 145.

[0038] In the example shown, the processing system 110 can include one or more programmable or special-purpose execution circuits capable of executing computing instructions. The memory 112 may be volatile or nonvolatile memory, such as read-only memory ("ROM"), random access memory ("RAM"), EEPROM, flash memory, or other memory technology. Those of ordinary skill in the art and others will recognize that memory 112 typically stores data or program modules that are immediately accessible to or currently being operated on by the processing system 110. In this regard, the processing system 110, including one or more processors, may serve as a computational center of the acoustic imaging device 102 by supporting the execution of instructions.

[0039] The acoustic sensor array 120 may include a plurality of spaced-apart acoustic sensors positioned to determine, based on the time and phase of receipt of acoustic signals, the direction, distance, and magnitude of signals emitted from an acoustic source. For example, in some implementations, the acoustic sensor array 120 may include up to 64 or more acoustic sensors spaced apart from each other, and configured to detect acoustic signals in a frequency band of between 2 kHz and 90 kHz at up to, or exceeding, 70 meters. Other frequency bands may be used as well, including those below 2 kHz and up to or exceeding about 100 kHz. Each sensor within the array is responsible for detecting and measuring the acoustic signals at a specific location. Each acoustic sensor within the array may be positioned in a specific spatial configuration, typically ina planar arrangement. The acoustic sensor array may include various signal amplifiers and / or analog to digital converter circuits, as well as a signal processing unit useable to extract relevant data from the acoustic sensor array. In some examples, the acoustic sensor array may include such a signal processing unit, while in other examples, the processing system 110 may perform signal processing. An example of such an acoustic sensor array 120 is depicted in Figs. 3-6, below.

[0040] The camera system 125 is positioned to capture an imaging field of view relative to the acoustic imaging device 102. The camera system captures image data, typically in a same direction of orientation as the acoustic sensor array 120, thereby allowing for display of image data with an overlay of acoustic signal data as described herein. In examples, the camera system 125 may be a digital still image camera, a video camera, or may include a plurality of camera devices. In example implementations, the camera system may include a digital camera configured to capture images at greater than 1 megapixel in image quality, and may have digital and / or optical zoom capabilities.

[0041] The display 130 may be any of a variety of display devices adapted for display of the image and acoustic information captured using the acoustic sensor array 120 and the camera system 125. In example implementations, the display 130 may be an LCD display and may be capable of receiving user input. In some examples, the display 130 is a touchscreen display, such as a capacitive touchscreen display.

[0042] The input devices 132 may include various additional input buttons or switches that are provided on the acoustic imaging device 102 beyond the touchscreen display. For example, in some instances, the input devices 132 may include a power button, an image capture button useable for image capture or to start / stop video capture, and the like.

[0043] The power subsystem 140 may include one or more power sources, such as a battery capable of providing electrical energy to the other components of the acoustic imaging device 102. In examples, the power subsystem 140 may include a rechargeable battery, such as a lithium-ion battery. Other battery types or power sources may be provided as well, such as a wired power connection.

[0044] The communication interface 150 may include one or more components for communicating with other devices, for example via a direct wired connection or over a network. Embodiments of the present disclosure may access basic services that utilize the communication interface 150 to perform communications using common network protocols. The communication interface 150 may correspond to a general purpose wired connection, such as a USB, Firewire, or analogous data connection, and / or may also include a wireless network interface configured to communicate via one or more wireless communication protocols, such as WiFi, 2G, 3G, 4G, 5G, LTE, WiMAX, Bluetooth, or the like.

[0045] In the example shown, a rotational speed sensor 145 may be integrated within the acoustic imaging device 102. The rotational speed sensor 145 may take a variety of forms. In one example embodiment, the rotational speed sensor 145 is implemented as a stroboscope. Such an example is seen in the embodiment illustrated in Fig. 4, below. In a further example embodiment, the rotational speed sensor 145 is implemented as a laser tachometer. Such an example is seen in the embodiment illustrated in Fig. 5, below. In still further example embodiments, the rotational speed sensor 145 may comprise circuitry used to process image data captured from camera system 125, for example to detect, from image frame analysis, a rotational speed of an object that is captured via an image sensor across a plurality of frames. By analyzing the phase and rotational position of the mechanical object, combined with the image of the item, rotational speed may be determined. An example of such rotational speed determinations based on image analysis is described in U.S. Patent No. 10,062,411, entitled “Apparatus and Method for Visualizing Periodic Motions in Mechanical Components”, the disclosure of which is hereby incorporated by reference in its entirety.

[0046] In the example shown, the acoustic imaging device 102 is communicatively connectable, via the communication interface 150, to one or more external devices, such as remote system 10 and / or rotational speed sensor system 180.

[0047] The remote system 10 may be implemented as a computing system, such as a desktop, laptop, or handheld portable computing system (e.g., a tablet, cellular telephone, or other mobile device). The remote system 10 includes a processing system 20, memory 22, display 30, input devices 32, and a communication interface 50, by way of example.

[0048] The processing system 20 and memory 22 are analogous to those described above as included in the acoustic imaging device 102. Display 30 may be an LED, LCD, OLED, or other type of display, and may be implemented as a touchscreen or non-touchscreen display as well. The display 30 may be configured to present the various user interfaces described herein when image and acoustic data are received at the remote system 10 from the acoustic imaging device 102. Input devices 32 generally may include one or more buttons, touch inputs, and the like, which are dependent on the form factor of the remote system 10. The input devices 32 may include, for example, a keyboard, mouse, stylus, and the like.

[0049] The communication interface 50 is configured to provide wired and / or wireless communication with other devices, and can include, for example, a complementary connection to the communication interface 150 above. Via the communication interfaces 50, 150, the acoustic imaging device 102 and remote system 10 may exchange data captured via the acoustic sensor array 120 and camera system, and instructions from remote system 10, to allow for, e.g., local or remote storage of current and historical acoustic test data including acoustic data and image data,as well as remote control of the acoustic imaging device 102. The storage of current and historical acoustic test data may include storage of location information, acoustic signal levels, image data, test settings, and the like, and may be used, either alone or in combination with other test data, to determine or estimate a probability of degradation or failure of a target object that is the subject of acoustic imaging.

[0050] In accordance with aspects of the present disclosure, it is noted that some or all of the features of the acoustic imaging device 102 and / or remote system 10 may or may not be present in all implementations, and that such devices may include other functionalities and features (e.g., remote control features, mobility features, and the like) not described here. Generally speaking, the acoustic imaging device 102 and remote system 10 may be configured with a display capable of depicting the user interfaces described herein, either in real-time as part of control of the acoustic imaging device 102 or based on stored data and / or data transmitted from the acoustic imaging device 102 to the remote system 10. It is also noted that the acoustic imaging device and remote system may be referred to as a first computing device and / or a second computing device in aspects of the present disclosure and claims appended hereto.

[0051] The rotational speed sensor system 180 may be remotely located from the acoustic imaging device 102, or may be a separate device from the acoustic imaging device 102 that is in communication with the acoustic imaging device. The rotational speed sensor system 180 is entirely optional within the system 100 described herein, but represents an example of a rotational speed sensor that is separate from the acoustic imaging device 102 and which provides rotation speed information to that device for further analysis and processing. In the example shown, the rotational speed sensor system 180 includes a processing system 182, a memory 183, a rotation sensor 184, as well as optionally, one or more input devices 185 and a communication interface 190.

[0052] The processing system 182 can include one or more programmable or special-purpose execution circuits capable of executing computing instructions. The memory 183 may be volatile or nonvolatile memory, such as read-only memory ("ROM"), random access memory ("RAM"), EEPROM, flash memory, or other memory technology. Those of ordinary skill in the art and others will recognize that memory 183 typically stores data or program modules that are immediately accessible to or currently being operated on by the processing system 182. In this regard, the processing system 182, including one or more processors, may serve as a computational center of the rotational speed sensor system 180 by supporting the execution of instructions.

[0053] The rotation sensor 184 may be any of a variety of types of rotation sensors. In examples, the rotation sensor 184 may include a stroboscope or laser tachometer as noted above. The rotation sensor 184 may also be a camera positioned external to the acoustic imaging device102 and configured to detect rotation speed via frame rate analysis, as noted above. The camera may in alternative embodiments, or in the same embodiment, be used to capture images of user interfaces or labels presented on mechanical equipment, and configured to perform optical character recognition to obtain rotation speed from such displays. In further embodiments, the rotation sensor 184 may, because it is separate or remote from the acoustic imaging device 102, be a tachometer physically interfaced to mechanical equipment to monitor rotational speed. The rotation sensor 184 may further be integrated into the mechanical equipment itself, and may be embodied as a communication interface from the mechanical equipment at which a data input signal indicative of rotational speed is provided to the acoustic imaging device. In still further examples, the rotation sensor 184 may be a magnetic sensor positioned in proximity to the mechanical equipment, such that the processing system 182 may be able to detect changes in a magnetic field of the mechanical equipment and detect particular periodicity of such changes as may be indicative of rotation speed; these signals, or the derived rotation speed, may be provided to the acoustic imaging system, either via wired or wireless connection.

[0054] The one or more input devices 185 may include input devices that are separate from the acoustic imaging device 102 but which are configured to receive manual input regarding rotation speed. For example, a manual entry device of mechanical equipment or other discrete system may allow manual override or entry of settings associated with rotational speed which may also be communicated to the acoustic imaging device 102.

[0055] The communication interface 190 corresponds to an interface capable of communicating via a common communication protocol with the communication interface 150 of the acoustic imaging device 102. For example, the communication interface 190 may correspond to a general purpose wired connection, such as a USB, Firewire, or analogous data connection, and / or may also include a wireless network interface configured to communicate via one or more wireless communication protocols, such as WiFi, 2G, 3G, 4G, 5G, LTE, WiMAX, Bluetooth, or the like. The communication interface 190 is configured to receive commands from the acoustic imaging device (e.g., initiating a rotational speed capture occurrence) and transmit sensed rotational speed to the acoustic imaging device.

[0056] Although shown in Fig. 1 that the remote system 10 and rotational speed sensor system 180 are communicatively connected to the same communication interface 150 of the acoustic imaging device 102, it is recognized that each of these systems may communicate using different wired and / or wireless communication protocols, and may individually be present or absent from the overall system 100 as well. Accordingly, the communication interface 150 of the acoustic imaging device 102 is intended as exemplary and representative of a plurality of types of communication interfaces that may each be present within such a device.

[0057] Figs. 2-3 are schematic front and rear views of an acoustic imaging device 200 on which example aspects of the present disclosure may be implemented. The acoustic imaging device 200 is an example of a physical implementation of the acoustic imaging device 102 of Fig. 1, for example when implemented as a manual handheld unit.

[0058] As seen in Fig. 2, the acoustic imaging device 200 includes a touchscreen display 230 positioned within a housing 202. The touchscreen display may be controlled via manual touch operations on user interface elements, such as those described below. A power button 232a activates the acoustic imaging device 200, and a capture button 232b initiates capture of concurrent image and acoustic data, either in still / instantaneous capture mode or a video / streaming mode.

[0059] On a rear side of the housing 202, an acoustic array 220 is mounted to the housing 202. The acoustic array 220 includes a plurality of acoustic sensors 222, for example miniaturized microphones, which are spaced apart from one another along two dimensions on the acoustic array 220. The plurality of acoustic sensors 222 determine, collectively, a direction and signal strength of an acoustic signal. The acoustic sensors 222 may also be used, in some cases, to determine a distance of the acoustic signal from the acoustic imaging device 200. This can be performed, for example, either alone or in combination with image data obtained by a camera 225. The camera 225 is positioned to be oriented in a direction normal to the plane defined by the plurality of acoustic sensors, such that the camera 225 captures a field of view in a direction from which acoustic signals may be sensed. In the example shown, the camera 225 is positioned in the center of the acoustic array 220; however, in other implementations, the camera may be located in other locations. In the example shown, a speaker / vent system 235 is also provided on the rear side of the housing 202, provides air communication into the housing 202, and allows emission of audible feedback, e.g., from a speaker.

[0060] In use, the acoustic imaging device 200 may be positioned or oriented toward an object of interest, for example such that the acoustic array 220 and the camera 225 are aimed at an object. A user may press a capture button 232b to initiate an acoustic sampling process, for example to capture image data and acoustic signals, and again to terminate capture (e.g. in video or streaming mode). Captured data may be displayed on the display 230, for example for manipulation and viewing.

[0061] Additionally, in use, the camera 225 may be used both for capturing images of objects within a field of view, but may also be used to capture a series of images in sequence (e.g., video frames) to determine a rotational speed of mechanical equipment located within that field of view. Such a process is described generally in U.S. Patent No. 10,062,411, previously incorporated by reference. In such instances, the camera 225 may, along with calculating circuitry, be considered a rotational speed sensor in addition to an imaging device, in the context of this disclosure.

[0062] Fig. 4 is a schematic plan view of an acoustic imaging sensor array 400 that may be integrated into an acoustic imaging device, according to example aspects of the present disclosure. The acoustic imaging sensor array 400 includes acoustic array 220, including acoustic sensors 222 as described above. The acoustic imaging sensor array 400 further includes a camera 225, also described above. In this example, a connector 402 allows for connection of the acoustic imaging sensor array 400 other electronic systems, for example as may be incorporated into a static mounted sensor system or onto a mobile device, such as a land-based mobile unit, airborne drone, or the like.

[0063] As noted above, an acoustic imaging device 200 or acoustic imaging sensor array 400 may be usable in a variety of applications. For example, acoustic signals may be emitted by pneumatic devices (e.g. detection of air leaks and the like), electrical devices (e.g. detection of sparks, periodic noise generated by electrical signals, and the like) and in some embodiments as described herein mechanical devices (e.g., bearings, rollers, or various other reciprocating or moving systems, such as motors, conveyors, gears and gearboxes, couplings fans, compressors, and mechanical robots.). In the particular case of mechanical devices, detection of acoustic signals emitted by a particular mechanical device may allow a user to determine the likely operational state that mechanical device. For example, operational mechanical devices may have a particular acoustic signature, while mechanical devices in varying states of operational wear or failure may exhibit other characteristics. For example, failing bearings or rotors may emit acoustic noise at higher frequencies that may be difficult to hear audibly, but which may be detected via the acoustic array 220. Other mechanical devices may exhibit wear or failure modes via other types of acoustic output. Additionally, electrical or pneumatic systems may also indicate the presence of failure by way of acoustic signals at various frequencies. Each of these acoustic characteristics may be difficult for even a skilled and highly-trained individual user of an acoustic imaging system to readily identify using the devices and systems currently available, in which acoustic response at an individual frequency is analyzed.

[0064] Referring to Figs. 5-6, schematic views of alternative embodiments of the acoustic imaging device of Fig. 2 are illustrated. The embodiments of Figs. 5-6 reflect incorporation of different types of rotational speed sensors into a handheld acoustic imaging device, to provide a compact, convenient device capable of capturing rotational speed information alongside image data and acoustic data associated with a particular field of view of the device. That is, Figs. 5-6 illustrate integration of a rotational speed sensor to allow for convenient, improved analysis of mechanical equipment by allowing for automatic detection of rotational speed and subsequent selection of one or more frequencies at which acoustic data should be captured and analyzed.

[0065] In the example shown in Fig. 5, a schematic rear plan view of acoustic imaging device 200 is shown. In this example, the rotational speed sensor 145 is implemented as a stroboscope 245. A stroboscope is a device used to make a cyclically moving object appear to move in slow motion or to appear stationary. The stroboscope 245 operates by emitting short, intense bursts of light at regular intervals, synchronized with the cyclic motion of the mechanical system being observed. The periodic flashing of light creates the appearance that the object is either moving slowly or not moving at all, depending on the settings of the stroboscope. The stroboscope 245 includes, in some embodiments, a laser sensor, and will generate strobing signals across frequency ranges until the laser sensor determines that the strobing rate is synchronized with the mechanical system being observed, thereby detecting rotational speed of such a system. This detected frequency may be used in combination with acoustic and image data for subsequent analysis, as discussed in further detail below.

[0066] In the example shown in Fig. 6, a schematic rear plan view of acoustic imaging device 200 is shown according to a still further embodiment. In this example, the rotational speed sensor 145 is implemented using a laser tachometer 345. A laser tachometer is a measuring device used to measure the rotational speed (RPM) of a rotating object, such as a motor, engine, conveyor belt, or any other machinery with a rotating component. A laser tachometer utilizes a laser beam to determine the RPM by measuring reflected light from a reflective target on the rotating object (e.g., on the mechanical equipment under test).

[0067] The acoustic imaging device 200 of Figs. 5-6 is otherwise similar to that of Fig. 3, and may be used to implement the acoustic imaging device of Fig. 1. As such, the camera 225 (along with analysis circuitry), stroboscope 245, or laser tachometer 345 represent examples of a rotational speed sensor 145 depicted therein, while other aspects of the acoustic imaging device may be common among those embodiments. However, in some examples, other features or functionality may be included within such an acoustic imaging device 102, 200 as described in Figs. 1-5 to implement acoustic imaging functionality without affecting the scope of the present disclosure. For example, in some instances, the acoustic imaging device 200 may lack a rotational speed sensor at all, and may rely on external devices or data to receive rotational speed. For example, a wired or wireless connection via the communication interface 150 to an external rotational speed sensor, or directly to mechanical equipment that exposes its rotational speed, may allow for similar analysis of acoustic data as described in Part II, below.II. Techniques for Acoustic Imaging Analysis Based on Rotational Speed

[0068] Referring now to Figs. 7-15, methods of and systems for performing analysis using an acoustic imaging device are described which are enabled by use of received, or detected, rotationalspeed. Generally speaking, such methods and systems include capture or receipt of rotational speed of a device to be analyzed, and selection of one or more frequencies within a range of acoustic frequencies in which to analyze acoustic response.

[0069] Referring first to Fig. 7, a flowchart of a method 700 of performing acoustic imaging on a mechanical system based on rotational speed of the mechanical system is provided. The method 700 may be performed, for example, using an acoustic imaging device, such as devices 102, 200 described above, either alone or in conjunction with one or more remote systems 10 and / or external rotational speed sensing systems 180.

[0070] In the example shown, the method 700 includes receiving a selection of a rotational speed source (step 702). For example, receiving a selection of a rotational speed source may include receiving, at a user interface presented on a display (e.g., displays 130, 230) of an acoustic imaging device, a selection from among any sensed available rotational speed sensors. In some examples, selection of the rotational speed source may be optional; for example, a default rotational speed sensor or source may be identified at the acoustic imaging device, such as in cases where the acoustic imaging device includes an integral rotational speed sensor. Example rotational speed sources may include, for example, a signal received from a visual stroboscope, a signal received from a laser tachometer, a signal received from a tachometer physically interfaced to the mechanical equipment, a data input signal received via a data port of the acoustic imaging device, a magnetic sensor positioned in proximity to the mechanical equipment and configured to detect changes in a magnetic field of the mechanical equipment, capture of a display of rotational speed via a camera system of the acoustic imaging device, or a manual input of rotational frequency at a user interface presented on the display of the acoustic imaging device.

[0071] In the example shown, the method 700 further includes determining a rotational speed of the mechanical equipment under test (step 704), for example utilizing the selected rotational speed source to obtain rotational speed of the mechanical equipment. Once the rotational speed is determined, the rotational speed may be saved (step 706) in association with a particular analysis project, for example within memory 112 of the acoustic imaging device and / or in memory 22 of a remote system 10.

[0072] In the example shown, the method 700 further includes determining, based on the rotational speed, one or more frequencies at which to perform acoustic imaging analysis (step 708). This determination may occur in a number of ways. In some examples, a lookup table may be used to determine corresponding frequencies or frequency ranges of acoustic signals to be analyzed based on a specific rotational speed detected, or based on the detected rotational speed falling within one or more speed ranges or classifications. For example, lower speed mechanical equipment may be best analyzed within comparatively lower range of acoustic frequencies(although some higher frequency signals may also be relevant), while higher speed mechanical equipment may be best analyzed within comparatively higher frequency ranges. Examples of such a classification and lookup are described below.

[0073] In other examples, an analysis model may be developed from known rotational frequencies and acoustic signals to generate a model useable to select frequency ranges of likely failures based on an input rotational speed. Such a model may be iteratively improved, either at the acoustic imaging device or at a remote system, as additional acoustic data is received and annotated with failure mode information and which may be used as training data for such a model.

[0074] In the example shown, the method 700 includes performing an automated acoustic analysis at the determined frequency range(s) (step 710). In some examples, performing automated acoustic analysis include capturing acoustic signals across an overall acoustic frequency range, and analyzing only those signals within a predetermined frequency or frequency range that is likely to include indications of degradation and / or failure of mechanical equipment operating at a particular rotational speed. In other examples, performing the automated acoustic analysis includes capturing acoustic signals only within the identified, predetermined frequency or frequency range(s) for subsequent analysis. In instances where the identified rotational speed is not available at the time acoustic signals are captured, such signals may be entered across a relevant acoustic frequency range, and analysis may later be performed using identified frequencies correlated to particular rotational speeds.

[0075] In addition to the automated analysis, the user interface may include additional features for validating such analysis using manual inputs. For example, a user may be allowed to input, into a user interface, an override frequency based on user knowledge. The user may also be able to toggle among frequencies, such as religion multipliers relative to a detected frequency, to validate that the frequency is the correct rotational frequency rather than a harmonic or multiple of that frequency. Further details regarding such user interface features are provided below.

[0076] Further, the method 700 can include generation of analysis results (step 712). Generation of analysis results can take a number of forms. In some examples, analysis results may be presented on a display 130, 230 of an acoustic imaging device 102, 200. Such results may be in the form of a user interface displaying a captured image of a field of view, with an overlay of acoustic data. The overlay of acoustic data may include a colored or gradated image depicting intensity of acoustic response within a selected set of frequencies.

[0077] Referring to Figs. 8A-8C, example sub-methods are described for identifying one or more frequencies for analysis based on rotational speed. The sub methods may be used, for example, at step 708 of Fig. 7 to determine relevant analysis frequency ranges based on a determined rotational speed of mechanical equipment to be tested.

[0078] In the example shown in Fig. 8A, a sub-method 800 includes determining, at operation 802, that a received rotational speed input is either above or below a threshold that defines a difference between a low speed mechanical system and a high-speed mechanical system. For example, a possible threshold of 300 revolutions per minute (RPM) might be used to define a difference between a low speed mechanical system and a high-speed mechanical system, with low speed mechanical systems and generally having acoustic response or failures in comparatively lower frequency ranges (e.g., at or below approximately 30 kHz), and high-speed mechanical systems generally having acoustic response or failures in comparatively higher frequency ranges (e.g., above 30 kHz, and often in a range of 40-75 kHz or up to 90 kHz, by way of example). In the example shown, if a low speed range is determined, a first set of frequency ranges may be selected (at step 804). If a high speed range is determined, a second set of frequency ranges may be selected (at step 806). Generally speaking, the frequency ranges that are selected may be either continuous or discontinuous with each other, and may be selected based on past experience or customized by a user in advance of analysis for detection of particular failure modes.

[0079] Although Fig. 8A illustrates separation into only low and high frequency ranges using a single threshold, it is recognized that other thresholds may be set, dividing an overall range of rotational speeds into different types or numbers of classifications (e.g., low, medium, high speed) with corresponding operational frequency ranges. Accordingly, sub-method 800 represents a generally simplistic way to quickly identify relevant frequency ranges for analysis in circumstances where a mechanical system is not well known (e.g. does not have significant historical data of acoustic response associated with failure modes of that system).

[0080] In the example shown in Fig. 8B, a sub-method 810 is illustrated in which a lookup table may be used to identify particular analysis frequencies to be used in response to a detected rotational speed. An example of such a lookup table is illustrated in Fig. 9A. Generally, based on a detected or determined rotational speed falling within a range defined within the lookup table, a specific frequency or frequency range may be selected for analysis. In some examples, if the rotational speed is not included within the entries in such a lookup table, one or more default analysis frequencies may be used by the acoustic imaging device.

[0081] Use of such a lookup table can allow for improved flexibility with respect to specific priest in association with particular relational deeds. Additionally, such a lookup table may be made editable on an acoustic imaging device, thereby allowing a user to customize the frequencies. Such a construct further improves the flexibility of setup of acoustic analysis, and may better tune analysis frequencies over time toward particular failures experienced by mechanical equipment operating at those speeds.

[0082] In a still further example shown in Fig. 8C, a sub-method 820 is illustrated in which an analysis frequency selection model may be used to identify multi-for analysis based on a given input of detected rotation speed. The sub-method 820 generally corresponds to use of a trained analysis frequency selection model, with an understanding that name will require training using historical data indicative of past observed failures of mechanical equipment, including both operating frequency of that mechanical equipment and acoustic signal responses captured from such equipment in correspondence with various failure degrees or failure modes.

[0083] In the example shown, the method includes providing the obtained rotation speed to the analysis frequency selection model (step 822). An example of such a model is illustrated below in conjunction with Fig. 9B, and can take any of a variety of forms as described therewith. The method further includes generating, from the model, one or more likely frequencies or frequency ranges in which failures are likely to be observed (step 824). In such an example, individual frequencies or frequency ranges may be associated with particular failure types or failure severity of a mechanical system operating at a known rotational speed.

[0084] Referring to Figs. 9A-9B, data structures useable to assist with selection of frequency ranges in response to detection of a rotational speed are illustrated. Fig. 9A illustrates a lookup table 900 useable to identify frequencies for analysis based on rotational speed, according to example embodiments. In this example, the lookup table includes a plurality of entries corresponding to different rotational speeds or rotational speed ranges. He for example, in trees with incremental rotational speeds of 100 revolutions per minute are illustrated, but may vary widely, may be discontinuous, and may be ranges of different sizes.

[0085] In the example shown, the lookup table 900 further includes a range classifier, in the example shown including low, medium, and high rotational speed classifications. Different types or numbers of range classifiers may be utilized as well. In this example, rotational speed ranges and range classifiers are associated with separate sets of analysis frequencies. The sets of analysis frequencies correspond to the frequencies where it has previously been determined that acoustic frequency analysis may be worthwhile to detect degradation and / or failure of mechanical equipment operating at the identified rotational speeds. It is noted that the sets of analysis frequencies may be discontinuous, may vary among the rotational speed ranges or classifiers, and may be editable or changeable by a user based on observation or experience. For example, entries within a lookup table 900 may be accessible and editable on a user interface of an acoustic imaging device such as described herein.

[0086] Fig. 9B illustrates a model framework 950 that includes an analysis frequency selection model 952 useable to identify acoustic frequencies for analysis, in accordance with an example embodiment. In the example as shown, a determined rotational speed is provided to theanalysis frequency selection model 952, which is trained to output one or more acoustic frequencies to be analyzed for that particular mechanical system and rotational frequency.

[0087] In the example as shown, the analysis frequency selection model 952 can take a number of forms. In some examples, the analysis frequency selection model 952 can be implemented as a supervised machine learning algorithm, such as a random forest, a support vector machine (SVM), or a neural network (e.g., a convolutional neural network or CNN), trained on labeled datasets of acoustic data, known failures, and failure frequency response. Additionally, the analysis frequency selection model 952 may be implemented using one or more unsupervised anomaly detection algorithms, such as isolation forests or autoencoders useable to detect unusual patterns in acoustic signals (particularly in instances where unexpected acoustic response might occur). Still further, mathematical or statistical models may be used to identify frequency ranges having a statistically high likelihood of having acoustic response data during degradation or failure events at particular frequencies or frequency ranges. Further, multiple types of models or techniques may be combined into an ensemble method to improve accuracy and / or robustness of failure detection.

[0088] As illustrated in the model framework 950, a user may perform frequency analysis using an acoustic imaging device, for example, and may also provide further analysis and manual feedback by labeling datasets captured with such a device. The manual feedback and labeling may include identification of observed failures or degradation that is present in conjunction with observation of a particular acoustic response. Such confirmed failure modes and other observations may be fed back to the analysis frequency selection model 952 to improve accuracy of frequency selections as additional or different types of degradation or failure responses are observed.

[0089] To ensure that the analysis frequency selection model 952 continues to improve, in some examples, that model is configured to recommend analysis at additional frequencies or frequency ranges to those at which failure or degradation has previously been observed, to ensure that different types of frequency response may be learned by the model. Additionally, although the acoustic analysis may be performed on an acoustic imaging device such as devices 102, 200, and a trained version of the analysis frequency selection model 952 may be maintained in a memory of such a device, it is recognized that training of such a model may take place at a remote system, such as remote system 10, to allow for aggregation of acoustic response and failure data from a plurality of such devices at different locations, monitoring different mechanical equipment, and experiencing different environmental conditions.

[0090] Referring to Figs. 10-13, example user interfaces illustrating methods of selection of rotational speed detection mechanisms at an acoustic imaging device, as well as for validation or override of detected rotational speed and subsequent analysis, are depicted.

[0091] Fig. 10 is an example user interface 1000 illustrating selection of a rotational speed input mechanism for use in acoustic imaging of mechanical equipment, according to example embodiments. In the example shown, the user interface 1000, including a field of view region 1001 and a frequency selection region 1004. The acoustic imaging user interface 1000 may be presentable on a display, such as displays 30, 130, 230. The field of view region 1001 displays image data associated with an image captured by a camera system of an acoustic imaging device, as well as an overlay of acoustic signals within a frequency range selected by a user within the frequency selection region 1004. In particular, the field of view region 1001 includes a focus indicator 1006. The focus indicator 1006 illustrates an area in which an acoustic imaging device is configured to focus image data and in which acoustic sensor data is likely most accurate (e.g., by being centered within the acoustic sensor array). In the example shown, the field of view region 1001 depicts a scene including a mechanical device 1050, such as a conveyor belt having a plurality of rollers 1052 each associated with bearing is allowing for rotation of the roller.

[0092] In the example shown, an operation selection menu 1002 is displayed as a menu bar, and presents a plurality of operating characteristics as options for selection. In the example shown, the operation selection menu 1002 allows for control of a mode (e.g., a mechanical mode in this case), memory management of on-device memory, acoustic signal settings, as well as annotation settings including a color palette usable for the acoustic overlay, markers that may be applied as part of the acoustic overlay and the like.

[0093] Based on selection of a mechanical acoustic analysis mode using the operation selection menu 1002, in some examples, a pop-up menu 1020 is presented that displays a plurality of user-selectable options of available devices or mechanisms for capture or input of rotational speed. In the example shown, the user-selectable options include performing frame analysis using a camera associated with the acoustic imaging device, using an integrated or communicatively attached stroboscope or laser tachometer, receiving a rotational speed via a line input, receiving manual entry or override of a rotational speed, or image capture of a scene in which the rotational speed is depicted.

[0094] Fig. 11 is an example user interface 1100 depicting detected rotational speed and acoustic frequency analysis at a selected frequency range, in accordance with example embodiments. In this example, the mechanical device 1050 includes a display 1120 that depicts a current operational rotational speed of the mechanical device 1050. The display may be a static display, or may be dynamic, displaying current operating status of the mechanical device 1050.

[0095] In the example shown, the user interface 1100 includes a rotational speed indicator 1106 that depicts the detected rotational speed of the mechanical device 1050. The rotational speed indicator 1106 will display a detected rotational speed based on the selected rotational speed sensor or input identified at the acoustic imaging device as described above. For example, a stroboscope, laser tachometer, imaging analysis, and the like may be performed. Additionally, optical character recognition of a detected label or display object, such as display 1120, may be used to either set the detected rotational speed or validate a rotational speed detected other means.

[0096] Fig. 12 is a further example user interface 1200 depicting receipt of user-entered rotational speed, in accordance with example embodiments. In particular, in instances where it may be difficult to detect rotational speed because one or more rotational speed sensors are malfunctioning, not present, or are otherwise unable to obtain an accurate rotational speed, a user may manually enter rotational speed into the user interface 1200 at rotational speed input field 1206. It is noted that this rotational speed input into the rotational speed input field 1206 may be used to override a sensed rotational speed, or may be used to append a rotational speed to previous analysis that was performed prior to capture or annotation with rotational speed.

[0097] If applied to previous analysis, entry of a rotational speed may result in application of an acoustic data filter to select only particular acoustic frequencies (e.g., using the methods described above in conjunction with Figs. 7-9) to better display de-noised acoustic data. This application of rotational speed to existing analysis allows that previous analysis to be enhanced by appending rotational speed to acoustic data that already may be identified as indicating degradation or failure. Such data may be used for further analysis, comparison to other mechanical failures, or training of machine learning models, such as the analysis frequency selection model 952 described above.

[0098] It is noted that, in some instances, rotational speed sensors may detect a rotational speed that is a frequency multiple of an actual rotational speed. This is because some such speed sensors scan a frequency range to identify a rotational speed at which an object appears stationary (e.g., in the case of a stroboscope). Accordingly, it may be useful to a user of an acoustic imaging device to validate that the detected rotational speed (e.g., 60 RPM as depicted in the rotational speed indicator 1106) is correct, and that the rotational speed is not some variant thereof (e.g., 30 RPM, or 120 RPM). Accordingly, in Fig. 13, a further user interface 1300 includes a frequency switching selector 1302 that will present a half speed and a double speed option to a user based on the detected rotational speed. The user may select either option to change the presumed rotational speed of the mechanical equipment and validate whether the originally detected or subsequently selected rotational speed is in fact correct.

[0099] Referring to Figs. 10-13 generally, it is noted that these user interfaces are intended as exemplary rather than limiting. A wide variety of other ways in which acoustic frequencies may be selected for analysis are possible, and different visualizations of acoustic signal response are also available. Examples of such customization of frequencies for analysis, and visualizations of acoustic response, are depicted in U.S. Provisional Patent Application No. 63 / 506,563 filed June 6, 2023, entitled “User Interface for Acoustic Imaging Systems” and International Application No. PCT / US2024 / 032876 filed June 6, 2024, entitled “Acoustic Imaging Systems for Visual Diagnosis”, the disclosures of which are hereby incorporated by reference in their entirety.

[0100] Now referring to Figs. 14-15, generalized methods of acoustic imaging and analysis are described which utilize the principles described herein. The methods of Figs. 14-15 may utilize an acoustic imaging device such as the devices 102, 200 described herein, and analyze acoustic response by assessing relevant frequencies based on the rotational speed of mechanical devices under observation or test.

[0101] Fig. 14 is a flowchart of an example generalized method 1400 of performing acoustic imaging on a mechanical system based on rotational speed of the mechanical system. The method 1800 may be initiated by receiving a mode selection at an acoustic imaging device (step 1402). The mode selection may be an indication of operation in a mechanical acoustic imaging mode in accordance with example embodiments. Other acoustic imaging modes may be made available by an acoustic imaging device, such as imaging of electrical or hydraulic systems. If, at operation 1404, the mechanical mode is not selected, operation proceeds via an alternative flow to perform other types of analysis at the acoustic imaging device (not shown, not relevant to the present disclosure). If, at operation 1404, the mechanical mode is selected, an acoustic analysis at particular frequencies may be performed based on detected rotational speed (step 1406). The acoustic analysis may be performed in conjunction with the methods described above in Figs. 7- 9, and using the user interfaces of Figs. 10-13. Based on that acoustic analysis, a user interface may be presented on a display of the acoustic imaging device that presents acoustic signal strength at one or more identified frequencies (step 1408).

[0102] Within the general analysis flow depicted in Fig. 14, in some embodiments the acoustic imaging device may perform specific assessment of acoustic response within the frequency ranges that are identified for analysis, and may apply one or more scoring or thresholding techniques to identify a severity of an issue indicated by the acoustic response. Fig. 15 is a flowchart of an example method 1500 of determining degradation of a mechanical system using a severity analysis based on rotational speed of the mechanical system, in accordance with example embodiments. The method 1500 may be used, for example, as part of step 1408 of Fig. 14, above.

[0103] In the example shown, the method 1500 includes determining acoustic signal strength levels at the selected, identified frequencies that are based on rotational speed (step 1502). The determination of acoustic levels at selected frequencies may include subdividing the selected frequencies into particular frequency bands, including frequency bands that are more likely indicative of typical operation, or degradation, or even failure. For example, for a generally low speed mechanical system, lower frequencies, on the order of 15-25 kHz, may be indicative of degradation of such a system, while the addition of higher frequency acoustic information (e.g., at 30 kHz, 45 kHz, 60 kHz, and the like) may be a more serious degradation or impending failure. The method 1500 may further include displaying an acoustic response overlay on the acoustic imaging device over an image of the mechanical device under test (step 1504). The acoustic response overlay may represent an aggregate acoustic signal strength across all of the selected frequencies, or may represent acoustic signal strength within identified frequency ranges.

[0104] In the example shown, the method 1500 further can include, in some embodiments, performing a scoring of selected frequencies within the frequency ranges identified for that particular rotational speed (step 1506). The scoring of selected frequencies may take a variety of forms. In some examples, scoring of selected frequencies may include identifying a threshold acoustic level within a sub frequency range or at a particular frequency that is that is below, within, or above predetermined signal intensity ranges.

[0105] At operation 1508, a determination is made regarding whether aggregate signal strength or individual frequency range signal strengths are within predetermined thresholds indicating potential degradation or failure. If no acoustic levels indicate problems, optional messages indicating correct operation may be displayed, as well as other informational messaging (step 1510). On the other hand, based on signal levels or scores being within a problem threshold, an acoustic imaging device may present one or more acoustic response alerts (step 1512). Such acoustic response alerts may be in addition to a color-coded acoustic response overlay, and may include messages indicating potential severity of degradation, or other graphical depictions of potential degradation. Various methods of display of such degradation are described in U.S. Provisional Patent Application No. 63 / 506,563, entitled “User Interface for Acoustic Imaging Systems” and International Application No. PCT / US2024 / 032876, entitled “Acoustic Imaging Systems for Visual Diagnosis”, previously incorporated by reference.

[0106] Referring to Figs. 1-15 generally, it is noted that the incorporation of rotational speed to assist with both identification of relevant acoustic frequencies at which to perform acoustic imaging analysis, as well as analysis of individual frequency responses whose severity may be determined to be different based on the detected rotational speed has a number of advantages. In particular, the features described herein simplify the use of an acoustic imaging device for analysisof mechanical systems, while better detecting and identifying degradation and failure by attributing such issues to some frequencies within an overall analyzed range of frequencies. Additionally, by automatically identifying rotational speed and selecting a subset of frequencies for analysis, significant computational savings may be achieved. Other advantages are apparent as well from the above disclosure and the appended claims.

[0107] Still referring generally to Figs. 1-15, functionality of computing devices described herein may be implemented in computing logic embodied in hardware or software instructions, which can be written in a programming language, such as C, C++, COBOL, JAVA™, PHP, Perl, HTML, CSS, JavaScript, PythonScript, VBScript, ASPX, Microsoft .NET™ languages such as C#, or the like. Computing logic may be compiled into executable programs or written in interpreted programming languages. Generally, functionality described herein can be implemented as logic modules that can be duplicated to provide greater processing capability, merged with other modules, or divided into sub-modules. The computing logic can be stored in any type of computer- readable medium (e.g., a non-transitory medium such as a memory or storage medium) or computer storage device and be stored on and executed by one or more general-purpose or specialpurpose processors, thus creating a special-purpose computing device configured to provide functionality described herein.

[0108] Many alternatives to the systems and devices described herein are possible. For example, individual modules or subsystems can be separated into additional modules or subsystems or combined into fewer modules or subsystems. As another example, modules or subsystems can be omitted or supplemented with other modules or subsystems. As another example, functions that are indicated as being performed by a particular device, module, or subsystem may instead be performed by one or more other devices, modules, or subsystems. Although some examples in the present disclosure include descriptions of devices comprising specific hardware components in specific arrangements, techniques and tools described herein can be modified to accommodate different hardware components, combinations, or arrangements. Further, although some examples in the present disclosure include descriptions of specific usage scenarios, techniques and tools described herein can be modified to accommodate different usage scenarios. Functionality that is described as being implemented in software can instead be implemented in hardware, or vice versa.

[0109] Many alternatives to the techniques described herein are possible. For example, processing stages in the various techniques can be separated into additional stages or combined into fewer stages. As another example, processing stages in the various techniques can be omitted or supplemented with other techniques or processing stages. As another example, processing stages that are described as occurring in a particular order can instead occur in a different order.As another example, processing stages that are described as being performed in a series of steps may instead be handled in a parallel fashion, with multiple modules or software processes concurrently handling one or more of the illustrated processing stages. As another example, processing stages that are indicated as being performed by a particular device or module may instead be performed by one or more other devices or modules.

[0110] The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and / or listed in the Request, including U.S. Provisional Application No. 63 / 607,857, filed December 8, 2023, are incorporated herein by reference, in their entirety. However, aspects of the present disclosure which are intended to be protected are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the claimed subject matter.

Claims

CLAIMS1. An acoustic imaging device comprising: an acoustic sensor array; a processing system communicatively connected to the acoustic sensor array; and a memory communicatively connected to the processing system, the memory storing instructions which, when executed by the processing system, cause the acoustic imaging device to: receive information indicating a rotational speed of a mechanical device; based on the rotational speed, select one or more frequencies at which to analyze acoustic data representing one or more acoustic signals from the mechanical device; and via the acoustic sensor array, capture the acoustic data at the one or more frequencies from an environment including the mechanical device.

2. The acoustic imaging device of claim 1, wherein the instructions further cause the acoustic imaging device to display a user interface including an image captured by a camera system and an overlay of information derived from the acoustic data captured at the one or more frequencies.

3. The acoustic imaging device of claim 2, wherein the acoustic data includes acoustic data captured within one or more frequency bands that are associated with historical failure modes of the mechanical device.

4. The acoustic imaging device of claim 3, wherein the one or more frequency bands are narrower than a frequency range of acoustic frequencies that the acoustic sensor array can sense, and the instructions further cause the acoustic imaging device to capture the acoustic data only within the one or more frequency bands.

5. The acoustic imaging device of claim 1, further comprising a rotational speed sensor communicatively connected to the processing system, wherein the rotational speed sensor is configured to sense the rotational speed of the mechanical device.

6. The acoustic imaging device of claim 5, wherein the rotational speed sensor is configured to sense the rotational speed of the mechanical device before the acoustic imaging device captures the acoustic data.

7. The acoustic imaging device of claim 5, wherein the rotational speed sensor comprises a stroboscope integrated into the acoustic imaging device.

8. The acoustic imaging device of claim 5, wherein the rotational speed sensor comprises a laser tachometer integrated into the acoustic imaging device.

9. The acoustic imaging device of claim 5, wherein the rotational speed sensor comprises at least one of: an image frame analyzer operatively connected to a camera system; or a mechanical rotation detector positioned to interact with the mechanical device.

10. The acoustic imaging device of claim 1, wherein the information indicating the rotational speed is received from a rotational speed sensor communicatively connected to the acoustic imaging device by a wireless connection.

11. The acoustic imaging device of claim 1, wherein the information indicating the rotational speed is received via image analysis of an image frame captured by a camera system, wherein the image frame includes data representative of indicia on the mechanical device indicating the rotational speed.

12. An acoustic imaging device comprising: an acoustic sensor array; a processing system communicatively connected to the acoustic sensor array; and a memory communicatively connected to the processing system, the memory storing instructions which, when executed by the processing system, cause the acoustic imaging device to: receive information indicating a rotational speed of a mechanical device; receive acoustic data from the acoustic sensor array, the acoustic data representative of one or more acoustic signals emitted from the mechanical device; and perform at least one of (1) automatically determining one or more frequencies at which to analyze the acoustic data based on the rotational speed, or (2) automatically determining a severity of degradation of the mechanical device based on a combination of the rotational speed and the acoustic data.

13. The acoustic imaging device of claim 12, wherein the information indicating the rotational speed of the mechanical device is received as a rotational speed input, the rotational speed input comprising at least one of: a signal received from a visual stroboscope; a signal received from a laser tachometer; a signal received from a tachometer physically interfaced to the mechanical device; a data input signal received via a data port of the acoustic imaging device; a magnetic sensor positioned in proximity to the mechanical device and configured to detect changes in a magnetic field of the mechanical device; capture of an image frame that includes data representative of indicia on the mechanical device indicating the rotational speed; capture of a sequence of image frames indicative of the rotational speed; or a manual input at a user interface of the acoustic imaging device.

14. The acoustic imaging device of claim 12, wherein the acoustic sensor array is configured to capture the acoustic data before the information indicating the rotational speed of the mechanical device is received.

15. The acoustic imaging device of claim 14, wherein the instructions further cause the acoustic imaging device to receive an input indicative of the rotational speed from a user at a user interface of the acoustic imaging device.

16. The acoustic imaging device of claim 12, wherein the instructions further cause the acoustic imaging device to capture, via the acoustic sensor array, the acoustic data at the one or more frequencies from an environment including the mechanical device.

17. A method of acoustic imaging, the method comprising: receiving, at an acoustic imaging device, information indicating a rotational speed of a mechanical device; based on the rotational speed, selecting one or more frequencies at which to analyze acoustic data representing one or more acoustic signals from the mechanical device; capturing, via a camera system, image data depicting the mechanical device; capturing, via an acoustic sensor array, acoustic data at the one or more frequencies from an environment including the mechanical device; anddisplaying an image including the image data depicting the mechanical device and an overlay of information derived from the acoustic data in at least a portion of the one or more frequencies.

18. The method of claim 17, wherein capturing the acoustic data includes capturing acoustic data within one or more frequency bands that are associated with historical failure modes of the mechanical device.

19. The method of claim 17, wherein receiving information indicating a rotational speed of mechanical device includes automatically detecting the rotational speed of the mechanical device using a rotational speed sensor integrated into the acoustic imaging device.

20. The method of claim 17, wherein selecting the one or more frequencies at which to analyze the acoustic data includes classifying the rotational speed according to a speed classification from among a plurality of speed classifications and selecting the one or more frequencies based, at least in part, on the speed classification.

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