5516 results about "Analog signal" patented technology

The invention discloses a multi-dimensional information integrated transformer health state monitoring method, which relates to the technical field of power systems, and comprises the following steps: deploying a multi-source sensor, collecting various signals of a transformer, and carrying out signal conditioning and analog-to-digital conversion on analog signals collected by the sensor; performing timestamp alignment on the received multi-source heterogeneous data, and eliminating data noise by adopting a filtering algorithm; key features which are sensitive to the health state of the transformer and complement each other are selected from the extracted feature values to form a health state evaluation index set; setting a sliding time window, obtaining historical data in the window, performing normalization processing on the data, calculating the information entropy and the variation coefficient of each index, and fusing the information entropy and the variation coefficient to obtain the dynamic weight of each index; obtaining a health state index of the transformer according to the normalized value and the dynamic weight; and displaying the health state index and the change trend thereof in real time, and setting an early warning threshold value and an alarm threshold value of the health state index.

The invention belongs to the field of fault diagnosis, and particularly relates to a main shaft bending common characteristic diagnosis system based on a stacking integration method, and the system comprises the following modules: a sensor module which is used for collecting a vibration signal of a main shaft in real time; the data acquisition and processing module is used for converting an analog signal into a digital signal and preprocessing the signal acquired by the sensor; the feature extraction module is used for extracting features from the preprocessed vibration signals; the machine learning diagnosis module analyzes and classifies the extracted features by using stack integration based on a plurality of trained machine learning models, and judges the health state of the main shaft; and the output module is used for outputting the diagnosis result and sending out an alarm signal when abnormality is detected. Real-time monitoring and automatic diagnosis of the main shaft bending fault are achieved, compared with a traditional method depending on expert experience and manual detection, the fault detection efficiency and accuracy can be greatly improved, and misjudgment and missed judgment risks caused by human factors are reduced.

This invention pertains to an intelligent electronic device designed for sophisticated monitoring and analysis of electrical power distribution. The device integrates at least one sensor for detecting electrical parameters from a distribution system to a load, coupled with an analog-to-digital converter to transform sensed analog signals into digital data. A processing module, linked to the converter, employs customized moving average filters to calculate the frequency of electrical power distribution, enhancing measurement accuracy by adjusting for transient fluctuations. It retrieves frequency threshold settings from memory to define operational bounds, logging frequency data around identified deviation events when measurements surpass these thresholds. This system facilitates precise frequency analysis and robust event logging, providing a comprehensive solution for maintaining electrical power distribution within defined standards.

The technology relates to enhancing performance of quantum sensor operation in a noisy environment. Quantum neural networks are used to pre- and post-process analog signals to which qubits of a quantum sensor are exposed. Intra-processing using additional quantum neural networks may also be employed. This approach filters out noise from both the input analog signal and the system itself to achieve a very high signal to noise ratio. This permits the system to detect induced dynamics associated during exposure of the qubits to the analog signals. This enables the quantum sensor to sense a change in a state of a system under test, which can be beneficial for areas such as imaging, magnetometry, sensing electric fields, optomechanical sensors, quantum radar and other areas where enhanced signal to noise ratios are desired.

According to the grid-connected line electric energy quality on-line detection device, the system comprises a broadband sensing module which is deployed on a grid-connected line to form an original analog signal; the conditioning module forms a standardized digital sampling signal; the edge calculation module receives the standardized digital sampling signal, analyzes a voltage effective value, a harmonic distortion rate, a sag depth and an event duration index in real time through a parallel calculation architecture, and forms an electric energy quality characteristic data set; the intelligent analysis module receives the electric energy quality characteristic data set to form an abnormal event report; and the communication interaction module receives the abnormal event report, encapsulates the abnormal event report into a standardized data frame through a configurable protocol stack, synchronously pushes the standardized data frame to the local monitoring terminal and the cloud management platform, receives an external control instruction and feeds back the external control instruction to the intelligent analysis module to optimize an analysis strategy. The grid-connected line electric energy quality on-line detection device can solve the problem that complex disturbance cannot be recognized in real time and cannot be accurately traced to the source.

The invention relates to an ultra-low power consumption multichannel high-speed signal synchronous acquisition and emission system suitable for satellite communication. The system comprises an acquisition and emission board card which mainly comprises a plurality of radio frequency transceivers, an optical module, a clock unit, an FPGA (Field Programmable Gate Array) 1 processor and the like; the clock unit comprises a clock chip, a clock Buffer and the like; the optical module is used for receiving data, sending the data to an FPGA (Field Programmable Gate Array) 1 for processing, then sending the data to a transmitting channel of the radio frequency transceiver through a JESD204B interface for interpolation filtering, QEC (Quadrature Error Correction) calibration and refreshing, and then performing up-conversion to output an I / Q analog modulation signal; a receiving channel of the radio frequency transceiver receives an I / Q analog signal, the I / Q analog signal is sampled after low-pass filtering, the sampled data is sent to the FPGA1 for processing through the JESD204B interface after QEC calibration, and then the data is forwarded through the optical module. The system can realize ultra-low power consumption and reduce the weight of the whole machine.

The invention relates to a system and a method for testing the conductivity of an engine wire harness, and relates to the field of intelligent detection, a programmable switch matrix is formed by acquiring a wire harness layout diagram and arranging matrix relays, and after logic self-inspection is executed, an optimal conduction path is searched based on a hierarchical partition model and a DFS algorithm; according to the method, the path image sets of the partitions are overlapped and mapped to identify abnormal wire harness sections, and finally, abnormity is determined through analog signal injection and waveform analysis and physical repair guidance is performed, so that the technical problems of low test efficiency, poor flexibility and difficulty in adapting to complex variable wire harness layout conductivity test are solved, and the purposes of improving the test flexibility and efficiency and reducing the test cost are achieved. And a fault point can be accurately positioned.

The invention relates to the technical field of exercise rehabilitation, and discloses a percutaneous spinal nerve electrical stimulation system and method, and the system comprises a power module which is used for converting an external alternating current into a stabilized power supply; the MCU module controls the pulse signal generation module; the pulse signal generation module is used for generating an electrical stimulation waveform; the DAC module receives the digital signal; the modulation module is used for receiving analog signals; the amplification module is used for receiving modulation waveforms; the multi-channel gating module is used for distributing stimulation current to a plurality of channels; the current detection module monitors the magnitude of current output by each channel in real time; and the ADC module performs digital conversion on the current analog signal output by the electrical stimulator. According to the invention, multi-channel and real-time modulation electrical stimulation signals can be output through modulation of two paths of stimulation signals, spinal cord sensory nerves are activated through the non-invasive epidermal electrode, amputation hand feeling is induced, the defect that electromyographic signals are interfered by the tail end of a stump in the prior art is improved, and the accuracy of an electromyographic signal decoding algorithm is also improved.

The invention discloses a multichannel electrophysiological signal acquisition system and an acquisition method thereof, and the multichannel electrophysiological signal acquisition system comprises a power supply module electrically connected with a controller, an analog front-end chipset, a filter module and an analog-to-digital conversion module; the analog front-end chip set is used for acquiring an analog signal and preprocessing the analog signal; the pre-processed analog signal is converted into a digital signal through a filter module and an analog-to-digital conversion module, and the digital signal is transmitted to a controller; the filter module is used for filtering and denoising; the timer module connected with the controller generates a sampling frequency, transmits the sampling frequency to the analog-to-digital conversion module, and provides a time sequence signal for the analog-to-digital conversion module. The invention discloses a multi-channel electrophysiological signal acquisition system, which solves the problem of synchronous sampling time sequence control of a high-density electrode array and eliminates signal phase deviation caused by clock jitter among multiple channels under the constraint of maintaining the total power consumption of the system. And real-time power frequency interference suppression is realized.

The invention discloses a method and system for measuring earth differential leakage current of a GIS shell, and relates to the technical field of leakage current detection, and the method comprises the steps: arranging a point position optimization scheme based on a sensor, arranging a current sensor, and synchronously obtaining a current signal collected by the current sensor; filtering the collected current signal by using a self-adaptive differential filter to obtain a real leakage current signal result; and performing real-time detection and analysis on signals of different frequency bands of a real leakage current signal result by using a multi-stage frequency domain filter. Based on a method of combining adaptive differential filtering, multi-sensor fusion, multi-frequency-domain analysis and intelligent threshold detection, the leakage current signal can still be accurately identified and extracted in a complex noise environment through the test of an analog signal, and the reliability and effectiveness of GIS equipment monitoring are guaranteed.

A temperature control device includes a temperature detector, a difference operation unit, a controller, a saturation processing circuit unit, a rewritable storage unit, and a conversion unit. The difference operation unit operates a digital value corresponding to a difference value between a detected temperature value and a target temperature. The controller calculates a manipulated variable using the digital value operated by the difference operation unit. The saturation processing circuit unit includes a digital circuit to limit an output value of the controller to a pre-set upper limit value. The rewritable storage unit stores the upper limit value read from a storage area of the rewritable storage unit and input into the saturation processing circuit unit. The conversion unit converts the output value of the saturation processing circuit unit into an analog signal to output the converted value as a control command value to the heater.

The invention discloses a dynamic neutral position and boundary self-calibration method and system of a joystick, and belongs to the technical field of engineering machinery and mining equipment control, and the method comprises the following steps: S1, electrifying equipment, and selecting a mode; s2, calibrating a dead zone; s3, setting a threshold value; s4, data storage; and S5, exiting and applying. According to the dynamic median and boundary self-calibration method and system of the joystick, when the joystick works, a physical manipulated variable is converted into an original electric signal through a joystick sensing unit, then the original electric signal is received through a signal processing module and subjected to signal conditioning, and an analog signal is converted into a digital signal which can be processed by a microprocessor; all logical judgments are executed through the main control unit, a user issues an instruction through a user configuration interface and directly inputs the instruction to the main control unit, the main control unit and the nonvolatile memory carry out bidirectional data interaction to realize permanent storage and calling of dead zone parameters, and the main control unit generates a final control instruction to be output after processing all information. And the actuating mechanism is driven.

A post-processing-based quantum random number extraction method, apparatus and device, and a computer readable storage medium, the method comprising: converting an analog signal output by a quantum entropy source into a digital signal through a preset high-speed ADC to obtain an original random number; calculating a minimum entropy according to the obtained original random number; updating a preset Toeplitz large matrix by taking the original random number as a seed so as to obtain a first random number sequence and a first extraction proportion output by the updated preset Toeplitz large matrix; according to the minimum entropy and the first extraction proportion, quantum random numbers are extracted from the first random number sequence, the technical problem that in the related technology, a Toeplitz matrix is usually generated through a pseudo-random number generator or cyclically calls stored seeds, and consequently the safety of the extracted random numbers is poor is solved, and the safety of the extracted random numbers is improved. The random number seed of the Toeplitz matrix is updated in real time by using the post-processed random number, the possibility that a random number generator is controlled and cracked by an attacker is avoided, and the security of the random number is guaranteed.

The invention discloses an intelligent underwater sound signal processing system and method based on multi-sensor data fusion, and belongs to the field of underwater signal processing. A plurality of sensors are used for collecting underwater sound signals, linear acceleration, angular velocity and other information of an underwater target and outputting continuous analog signals; then the differential signals are transmitted to a signal conditioning module, gain is dynamically adjusted according to target intensity, amplified differential signals are output to an analog-to-digital conversion module, high-precision digitalization is carried out through a 24-bit delta-sigma ADC, digital signals are output to a main control unit, and the main control unit carries out multi-sensor data fusion and target orientation calculation; and finally, the main control unit uploads the underwater acoustic signal and the equipment attitude information data to an upper computer through an RS485 bus for man-machine interaction. The scheme is based on multi-sensor data fusion, can realize high-precision target detection and positioning in a dynamic underwater environment, and has wide popularization and application values.

The invention provides an electrostatic driving micro-electro-mechanical device and a driving method thereof, the device comprises at least one electrostatic driving micro-electro-mechanical device, the device comprises a rotating support and at least one one-dimensional direction driving unit, and the first one-dimensional direction driving unit comprises a first electrode and a second electrode which are arranged in the first direction of the rotating support; the electrostatic drive micro-electromechanical device is further provided with a controller, the controller outputs digital signals to the digital-analog converter, the digital-analog converter outputs analog signals to the first electrode and the second electrode through the multi-way change-over switch, the multi-way change-over switch comprises a first selection switch, the first selection switch is a single-pole double-throw change-over switch, and the second selection switch is a single-pole double-throw change-over switch. A static contact of the first selection switch receives an analog signal output by the digital-to-analog converter, and a movable contact of the first selection switch selectively outputs the analog signal to the first electrode or the second electrode. The invention further provides a driving method of the driving device. The electrostatic driving micro-electro-mechanical device is compact in structure and low in production cost.

The invention discloses a multifunctional analog instrument acquisition card based on a ZYNQ-7000 chip and a data processing method. The acquisition card takes a ZYNQ-7000 series main control chip as a core, a PS end is responsible for data storage and network transmission, and a PL end covers a data acquisition module, a data output module, a data cache module and the like. A four-channel single-channel ADC circuit is adopted for data acquisition, and the data is cached and converted by FIFO and then transmitted to a PS end by DMA; the signal output module generates an analog signal according to an instruction of the upper computer; high-speed and stable data transmission is realized by means of multi-channel DMA; the Ethernet module guarantees communication with an upper computer. By utilizing the unique architecture of the ZYNQ chip and combining the cooperative operation of each functional module, the system has the advantages of modularization, high precision, high-speed processing, expandability and the like, effectively solves many defects of an existing data acquisition system, can be widely applied to analog signal acquisition and processing in multiple fields, improves the efficiency and precision of data acquisition and processing, and has a great market application prospect.

The invention provides a temporomandibular joint health state monitoring system and method based on joint vibration information, the system comprises a pasting touch type sound sensor, a microcontroller and an interactive display terminal, the pasting touch type sound sensor is used for pasting on a temporomandibular joint, obtaining a three-dimensional joint vibration analog signal, and sending the three-dimensional joint vibration analog signal to the microcontroller; the microcontroller carries out signal amplification, filtering processing and noise elimination, converts the signals into digital signals which can be identified and stored by the display terminal, and sends the digital signals to the interactive display terminal; the interactive display terminal is used for realizing real-time visual output of a three-dimensional joint vibration oscillogram and realizing an interaction function, and judging the health state of the temporomandibular joint based on an input maximum mandibular movement range, existence or absence of pain and joint noise parameters; on the basis of more comprehensive joint vibration information, real-time quantitative monitoring of the health state of the temporomandibular joint can be more accurately achieved, and a doctor can effectively and preliminarily screen the health state of the joint and a user can conduct self-monitoring at home conveniently.

The invention discloses a multi-channel AFE signal acquisition method and system based on adaptive adjustment, and the method comprises the steps: synchronously acquiring multi-channel analog signals through a multi-channel parallel AFE module, and configuring an independent programmable gain amplifier and an anti-aliasing filter for each channel; extracting time-frequency domain characteristic parameters of each channel signal in real time; dynamically generating an optimal adjustment strategy based on the time-frequency domain characteristic parameters, and adaptively adjusting the gain coefficient, the filtering bandwidth and the sampling rate parameter of each channel through a closed-loop feedback mechanism; and abnormal signal detection is realized by adopting an inter-channel cross validation algorithm, and automatic isolation of a fault channel and intelligent switching of a redundant channel are triggered. Through dynamic parameter intelligent adjustment, multi-channel cooperative fault tolerance and energy efficiency optimization architecture, the problems of signal distortion, response lag and high power consumption in a traditional multi-channel signal acquisition system are solved, and the signal fidelity and the system reliability are remarkably improved.

The invention discloses a temperature self-adaptive control system for organ perfusion, and belongs to the technical field of temperature control, and the system comprises a sampling unit which is used for converting analog signals of temperature, flow velocity and pressure of one or more target nodes in perfusion blood circulation into digital signals to form an initial data set; the calculation unit is used for performing wavelet transformation and moving average processing on the initial data set to construct a feature matrix, and establishing a temperature change prediction model based on the feature matrix so as to determine a temperature compensation amount in combination with dynamic correction; and the temperature control unit is used for adjusting the temperature control power by adopting a progressive strategy based on the temperature compensation amount and synchronously adjusting the blood flow rate so as to dynamically optimize the control parameters according to the temperature control effect. Through the scheme of the invention, the real-time regulation and control precision can be improved, and the quick response capability to temperature mutation is enhanced.

The invention provides an online monitoring method and device for partial discharge of GIS equipment, and relates to the field of online monitoring of high-voltage electrical equipment, and the method comprises the steps: collecting a partial discharge signal in the GIS equipment, and synchronously obtaining the data of an environment noise sensor; processing the acquired ultrahigh frequency signal based on the data of the environmental noise sensor to obtain a preprocessed analog signal; converting the preprocessed analog signal into a digital signal through a high-precision analog-to-digital converter; key characteristic parameters of the partial discharge signals are extracted from the digital signals; dynamically adjusting a discharge detection threshold according to the extracted key characteristic parameters by applying a hybrid optimization algorithm; and based on the adjusted discharge detection threshold, setting an event trigger condition, and when the detected partial discharge signal amplitude and the trigger frequency reach the event trigger condition, sending out an alarm signal. According to the invention, the partial discharge phenomenon can be detected and alarmed in time, so that the operation reliability and safety of the GIS equipment are improved.

The invention discloses a signal sampling method for a multi-channel signal converter, and the method comprises the steps: carrying out the synchronous and parallel sampling of an analog signal source according to a multi-channel signal collection module, so as to obtain multi-channel original signal sequence data; performing inter-channel time delay calibration and amplitude normalization processing on the multichannel original signal sequence data to obtain a calibrated multichannel signal data set; the invention relates to the technical field of signal processing. According to the signal sampling method for the multi-channel signal converter, the multi-channel signal converter improves the data consistency and accuracy through the technologies of synchronous sampling, time delay calibration, amplitude normalization and the like, meanwhile, precision adjustment of self-adaptive filtering, dynamic threshold segmentation and entropy driving is adopted, signal interference and abnormal data are reduced, and the signal quality is improved. The non-uniform resampling and compression technology is adopted to optimize the storage and transmission efficiency, key data is ensured to be transmitted preferentially, hardware is accelerated through an FPGA, and the real-time performance and the processing capacity of the system are improved.

The invention relates to the technical field of safety circuits, and provides a diagnosis method and circuit of a digital-to-analog conversion circuit, equipment and a medium. According to the method, two independent AI acquisition modules are arranged to respectively acquire analog quantity signals acquired at the same target measurement point, the acquired analog quantity signals are converted into digital signals through a built-in ADC circuit, and then the two paths of digital signals are transmitted to a safety logic module to be compared and judged; when the difference value of the two paths of digital signals is smaller than the preset safety threshold value, it is determined that the ADC circuit passes the diagnosis, and when the difference value of the two paths of digital signals is larger than or equal to the preset safety threshold value, it is determined that the ADC circuit does not pass the diagnosis, and therefore it is not needed to independently configure a DAC circuit for the ADC circuit in each AI collection module; the implementation difficulty and the implementation cost of the diagnosis circuit are reduced, the development period of the diagnosis circuit is shortened, and the diagnosis efficiency is improved.

The invention discloses a multi-channel analog-to-digital converter for multi-channel frequency division multiplexing and a conversion circuit and method thereof, and the frequency division multiplexing multi-channel analog-to-digital conversion circuit comprises an analog frequency conversion module which is used for receiving N paths of modulation clock signals, and generating N paths of modulation clock signals according to the modulation clock signals, n paths of input signals are modulated to preset frequencies of the input signals respectively, and N paths of modulation signals are obtained; wherein N is greater than or equal to 2, and N is a positive integer; the frequency bands where the N paths of modulation signals are located are not overlapped; the analog adder is used for combining the N paths of modulation signals to obtain one path of analog signal; the input end of the analog-digital conversion module is connected with the analog-digital conversion module; the digital logic control module is used for receiving the N paths of modulation clock signals and separating the digital signals into N paths of digital signals which are output in parallel. Multi-channel analog-to-digital conversion can be realized by adopting one analog-to-digital converter, the hardware volume, cost and power consumption can be reduced, and the analog-to-digital conversion rate and precision can be improved.

The invention discloses an output voltage detection method and system based on an aviation power supply, and relates to the technical field of aviation power supply voltage detection. A differential voltage sensor is connected to the output end of an aviation power supply, a high-frequency suppression capacitor is connected in parallel, the sampling rate of 20-50 times of the working frequency is set according to the type of the power supply, and the signals are collected and converted into analog voltage signals; the analog signal is subjected to two-stage filtering, is amplified to 0-5V through an instrument amplifier, and is converted into a digital voltage sequence through a 16-bit ADC (Analog to Digital Converter); calculating AC power supply effective value, peak value and other parameters, DC power supply average value, ripple coefficient and other parameters; comparing the characteristic parameters with a preset threshold value, determining that the characteristic parameters exceed the threshold value and recording related information; and a detection result is transmitted to a monitoring terminal through an RS485, data is locally stored, and a switching value is output to an alarm device when the data is abnormal. The method adapts to aviation power supply load fluctuation and environment temperature change, detection precision is high, data transmission and storage are safe, abnormity is accurately identified and early warning is carried out in advance, and aviation power supply operation and maintenance reliability and efficiency are improved.

The invention provides an intelligent mine management and control method and system based on the Internet of Things technology, and relates to the technical field of mine management and control, and the method comprises the steps: obtaining the roadway feature data and mining progress data of a mine in a mine; the influence degree on sensor signal transmission is calculated according to geological stress change data and equipment electromagnetic radiation intensity, and the distribution positions of the sensors are planned by combining roadway distribution data. And generating a sensor migration path plan, adjusting a point distribution position to obtain an optimized point distribution position, simulating a signal propagation path by adopting a Monte Carlo algorithm, and identifying a key area of which signal attenuation exceeds a preset threshold value. And adjusting the optimized point distribution position of the key area to obtain key area distribution points, and formulating a sensor distribution and control scheme in combination with the optimized point distribution position. According to the invention, the distribution positions of the sensors are optimized, the monitoring efficiency and the stability of signal transmission are improved, and the real-time monitoring and dynamic adjustment of the mine environment are realized.

The present application relates to a power distribution Internet of Things terminal debugging and testing system. The system comprises a cloud test service center (100), a power distribution Internet of Things terminal debugging device (200) and an intelligent gateway (300); the intelligent gateway (300) is used for acquiring terminal information of power distribution Internet of Things terminals and uploading the terminal information to the cloud test service center (100); the cloud test service center (100) is used for issuing a test command to the power distribution Internet of Things terminal debugging device (200) on the basis of the terminal information; the power distribution Internet of Things terminal debugging device (200) is used for carrying out signal conversion on the test command, determining an analog signal corresponding to the test command, and applying the analog signal to the power distribution Internet of Things terminals; the intelligent gateway (300) is used for acquiring digital signals and transmitting the digital signals to the cloud test service center (100), wherein the digital signals are obtained by converting the analog signal by the power distribution Internet of Things terminals; the cloud test service center (100) is used for determining test results of the power distribution Internet of Things terminals on the basis of the digital signals. Fully-automatic closed-loop debugging can be implemented, and the power distribution efficiency is greatly improved.

An electronic device may include a reception circuit configured to generate a plurality of reception data bits based on a voltage level of an analog signal received through a link, and to generate a plurality of bit reliability values indicating probabilities of error occurrence of the plurality of reception data bits based on the voltage level of the analog signal, an alignment circuit configured to group the plurality of reception data bits into a plurality of error correction code (ECC) symbols, and to generate a plurality of symbol reliability values indicating probabilities of error occurrence of the plurality of ECC symbols based on the plurality of bit reliability values, and a decoding circuit configured to correct errors of the plurality of ECC symbols based on the plurality of symbol reliability values.

The invention provides a downlink data transmission method, device and system for laser fiber power supply application, and the method comprises the steps: carrying out the differential coding of downlink data to be transmitted through a transmitting end, and obtaining a data bit sequence; mapping the data bit sequence into a modulation symbol sequence by adopting a single-carrier phase modulation mode; performing digital-to-analog conversion on the modulation symbol sequence to obtain an analog signal; and outputting downlink energy and downlink data through an energy optical fiber according to the analog signal. According to the invention, the signal frequency spectrum is moved to be far away from the direct current frequency through differential coding and single carrier phase modulation, so that the interference of direct current laser energy on signal detection is minimized, the signal-to-noise ratio is improved, the inter-symbol interference is reduced, and a receiving end is ensured to have enough signal-to-noise ratio to reliably detect data.

Systems, devices, methods, and implementations related to contact detection are described herein. In one aspect, a system is provided. The system includes a first piezoelectric microelectromechanical systems (MEMS) transducer coupled to configured to generate a first analog signal when the first analog signal is transduced from vibrations propagating through the object. The system includes a second piezoelectric MEMS transducer having configured to generate a second analog signal transduced from acoustic vibrations at a location of the object, and classification circuitry coupled to the output of first piezoelectric MEMS transducer and the output of the second piezoelectric MEMS transducer, where the classification circuitry is configured to process data from the first analog signal and data from the second analog signal, and to categorize combinations of the first analog signal and the second analog signal received during one or more time frames.