Patent Description:
Condition-Based Monitoring (CBM) is a practice for maintaining various types of equipment and assets by monitoring aspects of the equipment and assets using sensors. The sensors are used to monitor various parameters indicative of the operational condition of the equipment or asset. The sensed parameters are analyzed with the intention of identifying early performance degradation of the asset, with the intention of repairing the asset prior to failure or significant performance degradation, thereby reducing equipment downtime.

<CIT> describes, in accordance with its abstract, a rolling mill vibration signal separation method based on sparse feature similarity. The continuous rolling mill vibration signal separation method comprises the steps of: arranging acceleration sensors at one or more different positions on the surface of a sensitive part of a rotating component of a continuous rolling mill, and acquiring vibration signals, namely observation signals, of each vibration source during operation; acquiring sparse representation of each path of acquired vibration signals under an optimal atom set by adopting a sparse feature extraction method based on time-frequency spectrum segmentation; then clustering all atoms extracted through sparse representation according to structural similarity, estimating a number of vibration sources, and updating a sparse representation result by adopting the atoms corresponding to each clustering center; and finally, estimating a hybrid matrix based on a clustering coefficient corresponding to the new sparse representation result, and further calculating an independent signal of each vibration source to realize separation of vibration signals of the continuous rolling mill.

<CIT> describes vibration parameters which are determined from detected acceleration data. One accelerometer is used to detect measurement values from the corners of a triangle formed at arbitrary points on the mirror surface, and another accelerometer is used to detect measurement values from the mirror housing or vehicle body to which the mirror is fixed. The measurement values are fed to an analysis unit for data evaluation. An independent claim is included for an apparatus for detecting vehicle mirror vibration.

<CIT> describes a first vibration sensor measuring vibration of a bearing. A second vibration sensor for measuring background noise received by the first vibration sensor is installed so as not to receive vibration of the bearing. A data acquisition device receives a first signal that is a measurement signal of the first vibration sensor and a second signal that is a measurement signal of the second vibration sensor and outputs a third signal obtained by subtracting the second signal from the first signal as data indicating vibration of the bearing.

A computer-implemented method for determining vibrations generated by a device is provided according to claim <NUM>. A system for determining vibrations generated by a device is provided according to claim <NUM>. A non-transitory computer-readable storage medium is provided according to claim <NUM>.

The accompanying drawings, which are incorporated in and form a part of the Description of Embodiments, illustrate various non-limiting and non-exhaustive embodiments of the subject matter and, together with the Description of Embodiments, serve to explain principles of the subject matter discussed below. Unless specifically noted, the drawings referred to in this Brief Description of Drawings should be understood as not being drawn to scale and like reference numerals refer to like parts throughout the various figures unless otherwise specified.

The following Description of Embodiments is merely provided by way of example and not of limitation.

Reference will now be made in detail to various embodiments of the subject matter, examples of which are illustrated in the accompanying drawings. While various embodiments are discussed herein, it will be understood that they are not intended to limit to these embodiments. Furthermore, in this Description of Embodiments, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present subject matter. It should be noted and understood that there can be improvements and modifications made of the present invention described in detail below without departing from the scope of the invention as set forth in the accompanying claims.

Some portions of the detailed descriptions which follow are presented in terms of procedures, logic blocks, processing and other symbolic representations of operations on data within an electrical device. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. In the present application, a procedure, logic block, process, or the like, is conceived to be one or more self-consistent procedures or instructions leading to a desired result. The procedures are those requiring physical manipulations of physical quantities. Usually, although not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in an electronic system, device, and/or component.

It should be borne in mind, however, that these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the description of embodiments, discussions utilizing terms such as "determining," "comparing," "monitoring," "calibrating," "estimating," "initiating," "providing," "receiving," "controlling," "transmitting," "isolating," "generating," "aligning," "synchronizing," "identifying," "maintaining," or the like, refer to the actions and processes of an electronic item such as: a processor, a sensor processing unit (SPU), a processor of a sensor processing unit, an application processor of an electronic device/system, or the like, or a combination thereof. The item manipulates and transforms data represented as physical (electronic and/or magnetic) quantities within the registers and memories into other data similarly represented as physical quantities within memories or registers or other such information storage, transmission, processing, or display components.

Embodiments described herein may be discussed in the general context of processor-executable instructions residing on some form of non-transitory processor-readable medium, such as program modules, executed by one or more computers or other devices. The functionality of the program modules may be combined or distributed as desired in various embodiments.

In the figures, a single block may be described as performing a function or functions; however, in actual practice, the function or functions performed by that block may be performed in a single component or across multiple components, and/or may be performed using hardware, using software, or using a combination of hardware and software. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, logic, circuits, and steps have been described generally in terms of their functionality. Also, the example device vibration sensing system and/or electronic device described herein may include components other than those shown, including well-known components.

Various techniques described herein may be implemented in hardware, software, firmware, or any combination thereof, unless specifically described as being implemented in a specific manner. Any features described as modules or components may also be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. If implemented in software, the techniques may be realized at least in part by a non-transitory processor-readable storage medium comprising instructions that, when executed, perform one or more of the methods described herein. The non-transitory processor-readable data storage medium may form part of a computer program product, which may include packaging materials.

The non-transitory processor-readable storage medium may comprise random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), FLASH memory, other known storage media, and the like. The techniques additionally, or alternatively, may be realized at least in part by a processor-readable communication medium that carries or communicates code in the form of instructions or data structures and that can be accessed, read, and/or executed by a computer or other processor.

Various embodiments described herein may be executed by one or more processors, such as one or more motion processing units (MPUs), sensor processing units (SPUs), host processor(s) or core(s) thereof, digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), application specific instruction set processors (ASIPs), field programmable gate arrays (FPGAs), a programmable logic controller (PLC), a complex programmable logic device (CPLD), a discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein, or other equivalent integrated or discrete logic circuitry. The term "processor," as used herein may refer to any of the foregoing structures or any other structure suitable for implementation of the techniques described herein. As employed in the subject specification, the term "processor" can refer to substantially any computing processing unit or device comprising, but not limited to comprising, single-core processors; single-processors with software multithread execution capability; multi-core processors; multi-core processors with software multithread execution capability; multi-core processors with hardware multithread technology; parallel platforms; and parallel platforms with distributed shared memory. Moreover, processors can exploit nano-scale architectures such as, but not limited to, molecular and quantum-dot based transistors, switches and gates, in order to optimize space usage or enhance performance of user equipment. A processor may also be implemented as a combination of computing processing units.

In addition, in some aspects, the functionality described herein may be provided within dedicated software modules or hardware modules configured as described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of an SPU/MPU and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with an SPU core, MPU core, or any other such configuration. One or more components of an SPU or electronic device described herein may be embodied in the form of one or more of a "chip," a "package," an Integrated Circuit (IC).

Discussion begins with a description of an example electronic device including a motion sensor, upon which described embodiments can be implemented. An example system for determining vibrations generated by a device is then described, in accordance with various embodiments. Example operations for operating a system for determining vibrations generated by a device using motion sensors are then described.

In some environments, (e.g., factories and manufacturing facilities), there may be many sources of vibration (stationary, steady-state, or transient) that propagate through the space and are picked up by sensors on device being monitored, making it more difficult to attribute vibrations sensed by the sensor to the device being monitored rather than the surrounding environment. For example, multiple pieces of equipment in a factory floor with insufficient vibration dampening may cause vibrations not caused by a piece of equipment to be sensed by a sensor monitoring the piece of equipment. Furthermore, transient events, may further complicate the sensing of vibrations at a piece of equipment. For example, a forklift traveling by the piece of equipment, other equipment being turned on or off, and certain equipment with a variable vibration signature, can impact the sensed vibration at a motion sensor monitoring a piece of equipment.

Embodiments described herein describe systems and methods for determining vibrations generated by a device. First vibration measurements are received from a first accelerometer (or other motion sensor) coupled to the device, the first vibration measurements comprising a first device vibration contribution and a first environmental vibration contribution, wherein the device is located within an environment comprising a plurality of devices capable of generating vibrations. Second vibration measurements are received from a second accelerometer (or other motion sensor) located within the environment and not directly connected to the device, the second vibration measurements comprising a second device vibration contribution and a second environmental vibration contribution. The first vibration measurements and the second vibration measurements are compared. Based on the comparing, the first device vibration contribution is estimated. An operational condition of the device is determined based on the estimating, wherein the operational condition is indicative of device performance that may be impacted by device vibration contributions.

In accordance with the described embodiments, a motion sensing device, such as an accelerometer, is placed on or connected to an element of interest and another motion sensing device is placed nearby in the environment but not on the element of interest. For example, a motion sensor can be placed on a motor being monitored and a second motion sensor can be placed on the ground near the motor. In another example, a motion sensor can be placed on a segment of a moving robotic arm and a second motion sensor can be placed on the stationary body of the same robotic arm (e.g., the base). The motion sensors measure the vibrations from the element, device, or machinery being monitored and somewhere nearby or proximate the element being monitored as environmental reference. The described embodiments use differential vibration sensing to determine the vibrations of the element of interest, without any influence from any surrounding/environmental vibrations, by removing the vibrations not caused by the element of interest.

The described embodiments distinguish vibration from the element of interest from the vibrations coming from the surrounding environment. In one embodiment, the vibration is distinguished by determining which of the vibrations (e.g., at a certain frequency) is higher. For instance, a vibration component would be considered to be from the element of interest if the vibration amplitude is higher for the motion sensor connected to the element of interest rather than the sensor monitoring the environment. A first amplitude of the first vibration measurements at a particular frequency and a second amplitude of the second vibration measurements at the particular frequency are determined. The first amplitude at the particular frequency is compared to the second amplitude at the particular frequency. Estimating the first device contribution can include determining which of the first amplitude and the second amplitude is greater, and provided the first amplitude is greater than the second amplitude, determining that the device is generating vibrations.

In another embodiment, the vibration generated by the element of interest is quantitatively determined and isolated from all vibrations. Vibrations measured at the elements itself and at the reference position both measure vibrations from the element and from the environment. In some embodiments, the first device vibration contribution is determined using the first vibration measurements, the second vibration measurements, and a plurality of sensing coefficients for the first motion sensor (e.g., accelerometer) and the second motion sensor (e.g., accelerometer). In accordance with some embodiments, a plurality of sensing coefficients for the first motion sensor and the second motion sensor by receiving measurements from the first motion sensor and the second motion sensor under two conditions: <NUM>) receiving first calibration measurements from the first motion sensor and the second motion sensor while the device is not operational and only the environment is contributing vibrations, and <NUM>) receiving second calibration measurements from the first motion sensor and the second motion sensor while the device operates and the environment contributes same vibrations as the first calibration measurements.

In some embodiments, the first device vibration contribution is isolated from the first vibration measurements and the second vibration measurements, wherein the first device vibration contribution includes a first sensing coefficient multiplied by the actual device vibration contribution, the first environmental vibration contribution includes a second sensing coefficient multiplied by the actual environmental vibration contribution, the second device vibration contribution includes a third sensing coefficient multiplied by the actual device vibration contribution, and the second environmental vibration contribution includes a fourth sensing coefficient multiplied by the actual environmental vibration contribution. The operational condition of the device is determined using the first device vibration contribution.

Turning now to the figures, <FIG> is a block diagram of an example electronic device <NUM>. As will be appreciated, electronic device <NUM> may be implemented as a device or apparatus, such as an electronic motion sensing device. For example, such an electronic device may be, without limitation, a vibration sensing device that can be coupled to or affixed to equipment or assets in a factory or manufacturing plant.

As depicted in <FIG>, electronic device <NUM> may include a host processor <NUM>, a host bus <NUM>, a host memory <NUM>, and a sensor processing unit <NUM>. Some embodiments of electronic device <NUM> may further include one or more of a display device <NUM>, an interface <NUM>, a transceiver <NUM> (all depicted in dashed lines) and/or other components. In various embodiments, electrical power for electronic device <NUM> is provided by a mobile power source such as a battery (not shown), when not being actively charged. In other embodiments, electronic device <NUM> may only include sensor processing unit <NUM>, where sensor processing unit <NUM> includes componentry capable of transmitting data (e.g., motion sensing data) to other electronic devices or computer systems.

Host processor <NUM> can be one or more microprocessors, central processing units (CPUs), DSPs, general purpose microprocessors, ASICs, ASIPs, FPGAs or other processors which run software programs or applications, which may be stored in host memory <NUM>, associated with the functions and capabilities of electronic device <NUM>.

Host bus <NUM> may be any suitable bus or interface to include, without limitation, a peripheral component interconnect express (PCIe) bus, a universal serial bus (USB), a universal asynchronous receiver/transmitter (UART) serial bus, a suitable advanced microcontroller bus architecture (AMBA) interface, an Inter-integrated Circuit (I2C) bus, a serial digital input output (SOlO) bus, a serial peripheral interface (SPI) or other equivalent. In the embodiment shown, host processor <NUM>, host memory <NUM>, display <NUM>, interface <NUM>, transceiver <NUM>, sensor processing unit (SPU) <NUM>, and other components of electronic device <NUM> may be coupled communicatively through host bus <NUM> in order to exchange commands and data. Depending on the architecture, different bus configurations may be employed as desired. For example, additional buses may be used to couple the various components of electronic device <NUM>, such as by using a dedicated bus between host processor <NUM> and memory <NUM>.

Host memory <NUM> can be any suitable type of memory, including but not limited to electronic memory (e.g., read only memory (ROM), random access memory, or other electronic memory), hard disk, optical disk, or some combination thereof. Multiple layers of software can be stored in host memory <NUM> for use with/operation upon host processor <NUM>. For example, an operating system layer can be provided for electronic device <NUM> to control and manage system resources in real time, enable functions of application software and other layers, and interface application programs with other software and functions of electronic device <NUM>.

Display <NUM>, when included, may be a liquid crystal device, (organic) light emitting diode device, or other display device suitable for creating and visibly depicting graphic images and/or alphanumeric characters recognizable to a user. Display <NUM> may be configured to output images viewable by the user. It should be appreciated that display <NUM> is optional, as various electronic devices may not require a display device.

Interface <NUM>, when included, can be any of a variety of different devices providing input and/or output to a user, such as audio speakers, touch screen, real or virtual buttons, joystick, slider, knob, printer, scanner, computer network I/O device, other connected peripherals and the like.

Transceiver <NUM>, when included, may be one or more of a wired or wireless transceiver which facilitates receipt of data at electronic device <NUM> from an external transmission source and transmission of data from electronic device <NUM> to an external recipient. By way of example, and not of limitation, in various embodiments, transceiver <NUM> comprises one or more of: a cellular transceiver, a wireless local area network transceiver (e.g., a transceiver compliant with one or more Institute of Electrical and Electronics Engineers (IEEE) <NUM> specifications for wireless local area network communication), a wireless personal area network transceiver (e.g., a transceiver compliant with one or more IEEE <NUM> specifications for wireless personal area network communication), and a wired a serial transceiver (e.g., a universal serial bus for wired communication).

<FIG> shows a block diagram of an example sensor processing unit <NUM>, in accordance with various aspects of the present disclosure. SPU <NUM> comprises: a sensor processor <NUM>; internal memory <NUM>; and one or more sensors. With respect to SPU <NUM>, components showed in broken line (i.e., dashed boxes) may not be included in some embodiments. Accordingly, in some embodiments, electronic device <NUM> may additionally include one or some combination of: motion sensors <NUM> (e.g., gyroscope <NUM>, accelerometer <NUM>, a magnetometer <NUM>, and/or other motion sensors such as a pressure sensor <NUM> and/or an ultrasonic sensor <NUM>); temperature sensor <NUM>; and/or other sensors (e.g., a biometric sensor). In various embodiments, SPU <NUM> or a portion thereof, such as sensor processor <NUM>, is communicatively coupled with application host processor <NUM>, host memory <NUM>, and other components of electronic device <NUM> through interface <NUM> or other well-known means. SPU <NUM> may also comprise a communications interface (not shown) similar to interface <NUM> and used for communications among one or more components within SPU <NUM>.

Sensor processor <NUM> can be one or more microprocessors, CPUs, DSPs, GPUs, general purpose microprocessors, ASICs, ASIPs, FPGAs or other processors that run software programs, which may be stored in memory such as internal memory <NUM> (or elsewhere), associated with the functions of sensor processing unit (SPU) <NUM>. Sensor processor <NUM> operates to control and configure included sensors such as motion sensor(s) <NUM> and/or temperature sensor <NUM>. Sensor processor <NUM> may also run software programs for electronic device <NUM>, and/or for other applications related to the functionality of an electronic device <NUM>. In some embodiments, sensor processor <NUM> includes one or more of a performance module <NUM> and a calibration module <NUM>. These modules, when included, may be implemented in logic or in firmware, software, or a combination thereof that executes instructions upon sensor processor <NUM>. When not included, sensor processor <NUM> may simply perform the functions described herein with respect to performance module <NUM> and calibration module <NUM>. It should be appreciated that in some embodiments, the functions described as being performed by sensor processor <NUM> may also or alternatively be performed by host processor <NUM> or another communicatively coupled processor.

Performance module <NUM> may operate to monitor and/or set the performance specifications of the various sensors. For example, sensor processor <NUM> or a portion thereof, such as performance module <NUM>, may set the output data rate and full-scale data rate for the sensors. Performance module <NUM> may also monitor the performance of sensors that are internal and external to SPU <NUM> to make sure that the sensors are performing as required or as specified. It should be appreciated that performance module <NUM> may be external to SPU <NUM> (e.g., operated at a remote computer system such as control system <NUM>).

Calibration module <NUM> may operate to coordinate and perform calibration of a sensor in conjunction with another sensor. Embodiments described herein provide a plurality of motion sensors, one connected to or coupled to an asset being measured and one placed near the asset within the same environment, operating in conjunction for use in determining the true vibration contributions of an asset connected to or coupled to one of the motion sensors (e.g., sensor <NUM> of <FIG>). During calibration, measurements are made at both sensors under two conditions: <NUM>) where the asset is not operating (or does not generate vibration at frequency f) and only environment has vibration at frequency f; and <NUM>) the element operates and has vibration at frequency f with the same environment condition as the first condition. In various embodiments, SPU <NUM> and/or the asset can control the asset to perform the calibration (e.g., control operation of the asset), or can perform calibration opportunistically when it is determined that the asset is not operating (e.g., sensed by SPU <NUM>). It should be appreciated that calibration module <NUM> may be external to SPU <NUM> (e.g., operated at a remote computer system such as control system <NUM>).

in some embodiments, the calibration procedure may comprise calibration module <NUM> receiving a signal or message from an entity outside of SPU <NUM> to indicate that calibration is needed. When calibration is performed, sensor processor <NUM>, or a portion thereof such as calibration module <NUM>, may send a signal to one or more sensors to place the sensor(s) in a calibration mode and may also signal the sensor(s) about a window of time when a calibration measurement should be taken. It should be appreciated that in some embodiments, some, or all functions of calibration module <NUM> may be carried out by host processor <NUM> or by any processor disposed within electronic system <NUM>.

Condition-based monitoring (CBM) module <NUM> may operate to performance condition-based monitoring in conjunction with one or more SPUs <NUM>. For example, CBM module <NUM> can receive sensed motion data from the SPU <NUM> in which it is located and another SPU <NUM>, where one SPU <NUM> is located on a device within an environment and the other SPU <NUM> is located within the environment but not directly connected to the device. An operational condition of the device can be determined by using the motion data received from the two SPUs <NUM>, where the operational condition is indicative of device performance that may be impacted by device vibration contributions.

Internal memory <NUM> can be any suitable type of memory, including but not limited to electronic memory (e.g., read only memory (ROM), random-access memory (RAM), or other electronic memory). Internal memory <NUM> may store algorithms, routines, or other instructions for instructing sensor processor <NUM> on the processing of data output by one or more of the motion sensors <NUM>. In some embodiments, internal memory <NUM> may store calibration instructions for one or more motion sensors <NUM>. In some embodiments, memory <NUM> may store instructions for implementing one or both of performance module <NUM> and calibration module <NUM>.

Motion sensors <NUM>, when included, may be implemented as MEMS-based motion sensors, including inertial sensors such as a gyroscope <NUM>, or accelerometer <NUM>, or an electromagnetic sensor such as a Hall effect or Lorentz field magnetometer <NUM> (or some combination thereof). Other inertial sensors, such as an inclinometer may also be included. A pressure sensor <NUM> may also be included and used as a (vertical) motion sensor. In some embodiments, at least a portion of the motion sensors <NUM> may also, for example, be based on sensor technology other than MEMS technology (e.g., CMOS technology, etc.). One or more of the motion sensors <NUM> may be configured to provide raw data output measured along three orthogonal axes or any equivalent structure. Motion sensor(s) <NUM> are communicatively coupled with sensor processor <NUM> by a communications interface, bus, or other well-known communication means. When a version of electronic device <NUM> includes one or more motion sensors <NUM> and is affixed to, coupled with, or placed near to machinery or equipment, the motion (e.g., vibration) and/or orientation in space of the electronic device <NUM> are sensed by the motion sensor(s) <NUM> when the electronic device <NUM> is moved in space by the machinery or senses vibrations. In some embodiments, one of more of motion sensors <NUM> include a calibration mode that can be initiated by sensor processor <NUM>. In some embodiments, one or more of motion sensors <NUM> can determine when an out-of-calibration state exists and is/are configured to send a signal to sensor processor <NUM> or elsewhere to request calibration. The sensor may also send the calibration signal for other reasons other than an out of calibration state, such as surpassing a threshold of cycles or time since last calibration. This signal is referred to herein as a "calibrate me" signal or a "calibration signal," and identifies a need for calibration of the sensor which sends it. in some embodiments, sensors that do not have the ability to self-determine when calibration is needed are monitored by sensor processor <NUM>, performance module <NUM>, calibration module <NUM>, and/or another external entity to determine when calibration is required.

As discussed herein, various aspects of this disclosure may, for example, comprise processing various sensor signals indicative of device motion and/or orientation. These signals are generally referred to as "motion data" herein. Non-limiting examples of such motion data are signals that indicate accelerometer, gyroscope, and/or magnetometer data in a coordinate system. In other embodiments, the motion data can be vibrations sensed by a microphone. The motion data may refer to the processed or non-processed data from the motion sensor(s). In an example implementation, data from an accelerometer, gyroscope, and/or magnetometer may be combined in a so-called data fusion process, performed, for example, by sensor processor <NUM>, in order to output motion data in the form of a vector indicative of device orientation and/or indicative of a direction of device motion. Such a vector may, for example, initially be expressed in a body (or device) coordinate system. Such a vector may be processed by a transformation function that transforms the orientation vector to a world coordinate system. The motion and/or orientation data may be represented in any suitable reference frame, and may be represented in any suitable form, such as for example, but not limited to, quaternions, orientation matrices, Euler angles, and any of a variety of coordinate systems (e.g., the Unity coordinate system).

In some embodiments, electronic device <NUM> and/or sensor processing unit <NUM> may include a temperature sensor <NUM> or other means for sensing and determining the operating temperature and/or changes in the operating temperature of electronic device <NUM> and/or sensor processing unit <NUM>. In some embodiments, the motion sensor itself may comprise or be operable as a temperature sensor.

In accordance with the described embodiments, a motion sensing device, such as an accelerometer, is placed on or connected to an element of interest (e.g., an asset or a device) and another motion sensing device is placed nearby in the environment but not on the element of interest. The motion sensors measure the vibrations from the element, device, or machinery being monitored and somewhere nearby or proximate the element being monitored as environmental reference. The described embodiments use differential vibration sensing to determine the vibrations of the element of interest, without any influence from any surrounding/environmental vibrations, by removing the vibrations not caused by the element of interest.

<FIG> is a block diagram of an example environment <NUM> including assets and motion sensors, according to embodiments. As described herein, an environment <NUM> describes a location that includes a plurality of sources of vibration. Without limitation, an environment <NUM> can be a factory, a manufacturing facilities, a food processing plant, a power station, a shipyard, a distribution facility, etc. In general, environment <NUM> can be any space in which multiple assets generating vibrations are located.

As illustrated, example environment <NUM> includes assets <NUM>, <NUM>, and <NUM> having one or more associated motion sensors and control system <NUM>. As described herein, assets (also referred to herein as equipment) can include, without limitation, pumps, engines, motors, appliances, conveyer belts, robotic arms, etc. In general, assets include any device or machine that generates vibrations upon degradation of performance. It should be appreciated that environment <NUM> can include any number of assets, of which the illustrated example is one embodiment. Within environment <NUM>, there are multiple sources of vibration (stationary, steady-state, or transient), including assets <NUM>, <NUM>, and <NUM>, as well as other possible sources (e.g., forklifts, supply trucks, equipment being turned on or off, etc.).

Motion sensor <NUM> is coupled to or connected to asset <NUM>, and is configured to sense motion generated by asset <NUM>. It should be appreciated that motion sensor <NUM> is also capable of sensing motion generated within environment <NUM> due to the placement of asset <NUM> within environment <NUM>, dependent on the amplitude and frequency of such motion (e.g., distance from motion sensor <NUM>). Motion sensor <NUM> is positioned within environment <NUM> and is proximate asset <NUM>, but not directly connected or affixed to asset <NUM>. For example, motion sensor <NUM> may be located on the ground of environment <NUM> proximate asset <NUM>, or may be placed on a stationary element of asset <NUM> (e.g., a stationary body of a robotic arm). It should be appreciated that the sensed data may be raw vibration sensing data, set of features derived from the data, or events detected.

Motion sensor <NUM> is coupled to or connected to asset <NUM>, and is configured to sense motion generated by asset <NUM>. It should be appreciated that motion sensor <NUM> is also capable of sensing motion generated within environment <NUM>, dependent on the amplitude and frequency of such motion (e.g., distance from motion sensor <NUM>). Motion sensor <NUM> is positioned within environment <NUM> and is proximate asset <NUM>, but not connected or affixed to asset <NUM>.

Motion sensors <NUM> and <NUM> are coupled to or connected to asset <NUM>, and is configured to sense motion generated by asset <NUM>. It should be appreciated that motion sensors <NUM> and <NUM> can be coupled or connected to different elements of assets <NUM> (e.g., different arm segments of a robotic arm or different positions of a motor). It should be appreciated that motion sensors <NUM> and <NUM> are also capable of sensing motion generated within environment <NUM>, dependent on the amplitude and frequency of such motion (e.g., distance from motion sensors <NUM> and <NUM>). Motion sensor <NUM> is positioned within environment <NUM> and is proximate asset <NUM>, but not connected or affixed to asset <NUM>.

Control system <NUM> is a computer system configured to receive the motion sensing data from motion sensors of environment <NUM>, and to use differential vibration sensing to determine the vibrations of the assets <NUM>, <NUM>, and <NUM>, respectively, without any influence from any surrounding/environmental vibrations, by removing the vibrations not caused by the asset being sensed. It should be appreciated that the motion sensors of environment <NUM> can be connected to control system <NUM> via wired and/or wireless connections. It should be appreciated that control system <NUM> is optional in various embodiments. For example, the functionality of control system <NUM> may be performed by a CBM module (e.g., CBM module <NUM> of an SPU <NUM>) located within a motion sensor of environment <NUM>. It should further be appreciated that the condition-based monitoring can be performed by control system <NUM> in conjunction with a CBM module of a motion sensor of environment <NUM>.

It should be appreciated that, in accordance with various embodiments, the vibrations from the sensors are time synchronized to enable correlating appropriate measurements from the multiple sensors over a sequence of time. Synchronization can be done in the time domain or in the frequency domain. In some embodiments, time synchronization between the sensors can be performed at the system level using wired and/or wireless time synchronization and time keeping techniques.

In other embodiments, the described system allows for the self-synchronization in time measurements from two vibration sensors. For example, the sequence of vibration measurements can be compared between the two sensors. A common vibration characteristic or signature is detected in the data from both sensors that is used to synchronize time based from the two sensors and their data sequence. Use of the sequence of measurements over time to estimate drift between the two devices can be applied to measurement sequence to synchronize the data. There may be a lag between the sensors to measure a specific vibration. For example, vibration moves fast with different speed at different mediums and creating a phase lag between two sensor measurements that is resolved by performing the described self-synchronization.

In some embodiments, to deliver system level power efficiency, the reference vibration sensors may be held in low power standby when an element being monitored is not in use. For example, this can be done by the control system <NUM> knowing when an asset is on or off, or by the vibration sensor on an element being monitored detecting the equipment being on or off by analyzing the sensed vibrations present when equipment is on. in another example, two motion sensors in a self-contained CBM system (e.g., without an external control system <NUM>) can control each other for purposes of power mode control. The control system can send wake up/sleep commands through either a wired or wireless connection.

With reference to <FIG>, an illustration of assets <NUM>, <NUM>, and <NUM> within an example environment <NUM> is shown, according to embodiments. As illustrated, environment <NUM> shows a floor of a manufacturing facility, with assets <NUM> and <NUM> illustrated as robotic arms, and asset <NUM> illustrated as a conveyer belt. Motion sensor <NUM> is positioned on one element of asset <NUM>, motion sensor <NUM> is located on the stationary base of asset <NUM>, motion sensor <NUM> is positioned adjacent to the conveyer belt of asset <NUM>, motion sensor <NUM> is located on the stationary base of asset <NUM>, motion sensor <NUM> is positioned on one element of asset <NUM>, motion sensor <NUM> is positioned on another element of asset <NUM>, and motion sensor <NUM> is located on the stationary base of asset <NUM>. Motion sensors <NUM> and <NUM> that are placed within environment <NUM> may not be directly associated with any one asset, but may be used as a motion sensor for sensing environmental contributions. For example, motion sensors <NUM> and <NUM> may be placed on the ground somewhere within the manufacturing facility. It should be appreciated that motion sensors <NUM>, <NUM>, and <NUM>, as well as motion sensors <NUM> and <NUM>, can be used as a network of motion sensors for use in measuring the environmental affects across space of interest and enabling more precise interpolation of the environmental affects at the location where the asset is being monitored.

<FIG> is an illustration of an asset <NUM> and motion sensors <NUM> and <NUM> for monitoring the asset, according to embodiments. It should be appreciated that the placement of the different sensors depends on the type of sensor and the source/feature used for the monitoring. As illustrated in <FIG>, asset <NUM> is a robotic arm, where motion sensor <NUM> is positioned on an element of the robotic arm, and motion sensor <NUM> is located on the stationary base of asset <NUM>,.

In one example embodiment, motion sensors <NUM> and <NUM> measure the vibrations. These vibrations will include vibrations generated by asset <NUM> as well as vibrations generated by other sources of vibration within environment <NUM>. The described embodiments use differential vibration sensing to determine the vibrations generated by asset <NUM>, without any influence from any surrounding/environmental vibrations, by removing the vibrations not caused by asset <NUM>. The described embodiments allow for subtraction of the environmental effects and allow more precise classification of the element being monitored.

The environmental vibration sensed by motion sensors <NUM> and <NUM> are not the same, due to being positioned at different locations or because the vibration may be damped through media of asset <NUM>. Moreover, sensor orientation differences between motion sensors <NUM> and <NUM> (e.g., due to movement of asset <NUM>) can result in the sensing of different motion. The described embodiments are applicable to situations where sensors <NUM> and <NUM> are moving or are not moving, and have the same or different orientation, by aligning the axes of motion sensors <NUM> and <NUM>.

In some embodiments, the sensor orientation difference is overcome by projecting the orientation of motion sensor <NUM> onto the orientation of motion sensor <NUM> (where motion sensors <NUM> and <NUM> are <NUM>-axis or <NUM>-axis sensors) or by using the gravity vector (where motion sensors <NUM> and <NUM> are MEMS accelerometers). If <NUM>-axis sensor is used, motion sensors <NUM> and <NUM> should not be orthogonal to each other. The sensor measurement from one sensor should be converted to the reference frame of the other sensor. The differential sensing is then done in the same reference frame. For example, earth frame or gravity frame, as understood by one of ordinary skill in the art of sensor orientation. For example, if the sensor data is represented by vector X in the orientation <NUM>, it can be transformed to the orientation <NUM> by X' = R X, where R is the rotation matrix transforming coordinate system of orientation <NUM> to the coordinate system of orientation <NUM>, and X' is the projection of X in the orientation <NUM>. Converting axial measurement to magnitude can be also used to make it orientation agnostic.

The described embodiments distinguish vibration from asset <NUM> from the vibrations coming from the surrounding environment <NUM>. In one embodiment, the vibration is distinguished by determining which of the vibrations (e.g., at a certain frequency) is higher. For instance, a vibration component would be considered to be from asset <NUM> if the vibration amplitude is higher for motion sensor <NUM> rather than motion sensor <NUM>. in some embodiments, an amplitude of the vibration measurements of sensor <NUM> at a particular frequency and an amplitude of the vibration measurements of sensor <NUM> at the particular frequency are determined. The two amplitudes at the particular frequency are compared. The vibration contribution of asset <NUM> includes determining which of the amplitudes is greater, and provided the amplitude measured at motion sensor <NUM> is greater than the amplitude measured at motion sensor <NUM>, it is determined that asset <NUM> is generating vibrations. Determining that asset <NUM> is generating vibrations allows for determining an operational condition of the asset, where the operational condition is indicative of performance of the asset that may be impacted by asset vibration contributions.

In another embodiment, the vibration generated by the asset (e.g., element of interest) is quantitatively determined and isolated from all vibrations. Vibrations measured at the asset motion sensor (Sensorasset) and at the reference position motion sensor (Sensorenv) both measure vibrations from the asset and from the environment. For a given frequency f, consider Sensorasset and Sensorenv sensor measurements as: <MAT> <MAT> where:.

As shown in Equations <NUM> and <NUM>, Sensorasset(f) and Sensorenv(f) include contributions from both Asset(f) and Env(f). In some embodiments, the Asset(f) (e.g., the true element vibration contribution) is determined using the Sensorasset(f), Sensorenv(f), and a plurality of sensing coefficients A(f), B(f), C(f), and D(f). In some embodiments, for simplicity, A(f) = D(f) = <NUM>. Therefore, there are two coefficients to be calibrated: B(f) and C(f).

In accordance with some embodiments, a plurality of sensing coefficients for Sensorasset and the Sensorenv are determined during sensor calibration by receiving first calibration measurements from the Sensorasset and the Sensorenv while the asset is not operational and only the environment is contributing vibrations and receiving second calibration measurements from the Sensorasset and the Sensorenv while the asset operates and the environment contributes same vibrations as the first calibration measurements.

Continuing with the example of Equations <NUM> and <NUM>, for instance, to calibrate and determine sensing coefficients B(f) and C(f), measurements are taken for both the Sensorasset and the Sensorenv under two conditions:.

It should be appreciated that in other embodiments, the sensing coefficients can be calculated by modeling (numerical simulation) or modal analysis.

During operation of Sensorasset and the Sensorenv, where A(f) and D(f) are one, <NUM>(f) and C(f) are sensing coefficients determined during calibration, there are two measurements (Sensorasset(f) and Sensorenv(f)) and two equations. Accordingly, Asset(f) and Env(f) can be directly determined. Determining and monitoring Asset(f) allows for determining an operational condition of the asset, where the operational condition is indicative of asset performance that may be impacted by asset vibration contributions.

The described embodiments are helpful when there are similar vibration components existing in the environment and the asset. The described embodiments can be used for the raw vibration sensing data or a set of features derived from the sensing data. In some embodiments, it may be useful to model attenuation of vibration over space between the differential sensors.

In another embodiment, it may be desirable to deploy a network of synchronized sensors in the space to more precisely measure the environmental vibration contribution and develop a more accurate attenuation map using the network of motion sensors and their locations with respect to the location of element being monitored (e.g., using triangulation techniques).

The time synchronization will also enable buffering and sending accurately time tagged data in batches from each node thereby elevating hard real-time requirement at the system level. The data batches can be shared with processor engine at irregular times with uncontrolled latency. Accurately time tagged data may be raw vibration sensing data, set of features derived from the data, or events detected.

The described embodiments provide a CBM system including a plurality of motion sensors. Monitoring the device vibrations allows for the detection of changes in vibrational magnitude and/or frequency that are indicative of a change in the operational condition of the device. For example, detecting a vibrational frequency above a threshold frequency may indicate a degradation in performance of the device. A notification can be generated responsive to detecting such a change, notifying an individual responsible for managing device operations and repairs that the particular device should be investigated for potential repair.

<FIG> and <FIG> illustrate flow diagrams of example methods for determining vibrations generated by a device, according to various embodiments. Procedures of these methods will be described with reference to elements and/or components of various figures described herein. It is appreciated that in some embodiments, the procedures may be performed in a different order than described, that some of the described procedures may not be performed, and/or that one or more additional procedures to those described may be performed. The flow diagrams include some procedures that, in various embodiments, are carried out by one or more processors (e.g., a host processor or a sensor processor) under the control of computer-readable and computer-executable instructions that are stored on non-transitory computer-readable storage media. It is further appreciated that one or more procedures described in the flow diagrams may be implemented in hardware, or a combination of hardware with firmware and/or software.

With reference to <FIG>, flow diagram <NUM> illustrates an example process for determining vibrations generated by a device, according to some embodiments. At procedure <NUM> of flow diagram <NUM>, first vibration measurements are received from a first motion sensor (e.g., accelerometer) coupled to the device, the first vibration measurements comprising a first device vibration contribution and a first environmental vibration contribution, wherein the device is located within an environment comprising a plurality of devices capable of generating vibrations. At procedure <NUM>, second vibration measurements are received from a second motion sensor (e.g., accelerometer) located within the environment and not connected to the device, the second vibration measurements comprising a second device vibration contribution and a second environmental vibration contribution. In some embodiments, the first motion sensor and the second motion sensor are maintained in a low power standby mode when the device is not operational.

In some embodiments, as shown at procedure <NUM>, the first motion sensor and the second motion sensor are time synchronized. In some embodiments, as shown at procedure <NUM>, the first vibration measurements and the second vibration measurements are compared. At procedure <NUM>, a vibration characteristic present in both the first vibration measurements and the second vibration measurements is identified. At procedure <NUM>, the first motion sensor and the second motion sensor are time synchronized using the vibration characteristic.

in some embodiments, as shown at procedure <NUM>, alignment of the first motion sensor and the second motion sensor is determined. in some embodiments, as shown at procedure <NUM>, the directionality of vibration of the first motion sensor and the second motion sensor is aligned based on the alignment.

With reference to <FIG>, at procedure <NUM>, the first vibration measurements and the second vibration measurements are compared. As shown at procedure <NUM>, a first amplitude of the first vibration measurements at a particular frequency and a second amplitude of the second vibration measurements at the particular frequency are determined. At procedure <NUM>, the first amplitude at the particular frequency is compared to the second amplitude at the particular frequency. In another embodiment, as shown at procedure <NUM>, the first vibration measurements and the second vibration measurements are applied to equations using sensing coefficients.

At procedure <NUM>, based on the comparing, the first device vibration contribution is estimated. As shown at procedure <NUM>, which of the first amplitude and the second amplitude is greater is determined. At procedure <NUM>, provided the first amplitude is greater than the second amplitude, it is determined that the device is generating vibrations. In another embodiment, as shown at procedure <NUM>, the first device vibration contribution is determined using the first vibration measurements, the second vibration measurements, and a plurality of sensing coefficients for the first motion sensor and the second motion sensor. In some embodiments, as shown at procedure <NUM>, the first device vibration contribution is isolated from the first vibration measurements and the second vibration measurements, wherein the first device vibration contribution comprises a first sensing coefficient multiplied by the actual device vibration contribution, the first environmental vibration contribution comprises a second sensing coefficient multiplied by the actual environmental vibration contribution, the second device vibration contribution comprises a third sensing coefficient multiplied by the actual device vibration contribution, and second environmental vibration contribution comprises a fourth sensing coefficient multiplied by the actual environmental vibration contribution.

At procedure <NUM>, an operational condition of the device is determined based on the estimating, wherein the operational condition is indicative of device performance that may be impacted by device vibration contributions. As shown at procedure <NUM>, the operational condition of the device is determined using the first device vibration contribution. In some embodiments, as shown at procedure <NUM>, first device vibration contributions are monitored over time to detect a change in the operational condition of the device.

The examples set forth herein were presented in order to best explain, to describe particular applications, and to thereby enable those skilled in the art to make and use embodiments of the described examples. However, those skilled in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. Many aspects of the different example embodiments that are described above can be combined into new embodiments. The description as set forth is not intended to be exhaustive or to limit the embodiments to the precise form disclosed.

Claim 1:
A computer-implemented method for determining vibrations generated by a device (<NUM>, <NUM>, <NUM>), the method comprising:
receiving (<NUM>) first vibration measurements from a first accelerometer (<NUM>, <NUM>, <NUM>, <NUM>) coupled to the device, the first vibration measurements comprising a first device vibration contribution and a first environmental vibration contribution, wherein the device is located within an environment (<NUM>) comprising a plurality of devices (<NUM>, <NUM>, <NUM>) capable of generating vibrations;
receiving (<NUM>) second vibration measurements from a second accelerometer (<NUM>, <NUM>, <NUM>) located within the environment and not connected to the device, the second vibration measurements comprising a second device vibration contribution and a second environmental vibration contribution;
comparing (<NUM>) the first vibration measurements and the second vibration measurements;
based on the comparing, estimating (<NUM>) the first device vibration contribution; and
determining (<NUM>) an operational condition of the device using the first device vibration contribution,
wherein the operational condition is indicative of device performance that may be impacted by device vibration contributions, characterized in that the comparing the first vibration measurements and the second vibration measurements comprises:
determining a first amplitude of the first vibration measurements at a particular frequency and a second amplitude of the second vibration measurements at the particular frequency; and
comparing the first amplitude at the particular frequency to the second amplitude at the particular frequency, wherein the estimating the first device vibration contribution comprises:
determining which of the first amplitude and the second amplitude is greater; and
provided the first amplitude is greater than the second amplitude, determining that the device is generating vibrations.