Sensor Signal Conditioning Research Articles

Damage-related imbalance identification for UAV composite propeller blades based on bidirectional temporal convolutional network and a flexible sensing system

Abstract Damage to the composite propeller blades could lead to rotational imbalance, which seriously affects the operational safety of unmanned aerial vehicles (UAVs), therefore, a novel method combining the Teager energy operator (TEO) and bidirectional temporal convolutional network (BiTCN) is proposed for detecting, localizing, and quantifying the damage-related imbalance in the blades. A flexible sensing system that contains Micro electro mechanical sensor accelerometers, signal conditioning, and wireless transmission is integrated with the composite propeller for in-situ signal acquisition of the propeller blades. TEO is applied to demodulate and enhance the pulse compositions in vibration signals and singular value decomposition (SVD) is employed to suppress random noise, resulting in denoised Teager energy spectrums for model input. Temporal convolutional network (TCN) has been widely used in sequence signal modeling because the causal dilated convolution could learn the context information of sequence signals while maintaining the advantages of parallel computing. To fully extract the signal features, BiTCN models are established to learn both the forward and backward signal features. Experimental verification results show that the proposed method detects the existence of imbalance with 100% accuracy, and the accuracies of localization and quantization are 99.65% and 98.61%, respectively, which are much higher than those of the models with the original signal as input. In addition, compared with the other four different algorithms, BiTCN is superior in terms of convergence speed and prediction accuracy.

(Invited) Organic Source-Gated Transistors for High-Gain Sensor Signal Conditioning

A set of important developments have been recently demonstrated in contact-controlled thin-film transistors [1-3] realized with organic semiconductors.Targeted at obtaining superior power efficiency, layout utilization and signal integrity, these advances largely focus on the electrical and geometrical optimization of the source area. Field-relief structures embedded into the source contact produce high intrinsic gain in both n-type and p-type inkjet-printed organic source-gated transistors (SGTs) [4-5], toward achieving the potential of such devices in high gain unipolar amplifiers [6]. Thermal effects are reduced via contact barrier – semiconductor interplay [7] and robust optical sensing of blue light is demonstrated [8]. Finally, utilizing the source barrier, as opposed the W/L geometry of the transistor to dictate drain current magnitude leads to compact and practical CMOS inverters when p-type DNTT-based organic SGTs are paired with n-type IGZO SGTs [9].By judicious and application-driven design (Figure 1) [10], the source-gated transistor and its evolution, the multimodal transistor [11], are showing significant potential in signal conditioning and sensing applications.[1] J. M. Shannon et al., IEEE Trans. Electron Devices, 60, 2444–2449 (2013).[2] A. Valletta et al., J. Appl. Phys. 114 064501 (2013).[3] J. Zhang, et al., PNAS 116, 4843 (2019).[4] Y. Hemmi, et al., Nanomaterials, 12, 4441 (2022).[5] Y. Hemmi, et al., Adv. Electron. Mater., 9, 2201263 (2023).[6] E. Bestelink, et al., IEEE Sens. J., 20 (24), 14903 (2020).[7] E. Bestelink, et al., Adv. Electron. Mater., 9, 2201163 (2023).[8] E. Bestelink, et al., Adv. Opt. Mater., 2301931 (2023).[9] E. Bestelink, et al., J. Mater. Chem. C, 11, 11688 (2023).[10] E. Bestelink, et al., Adv. Electron. Mater., 8, 2101101 (2021).[11] E. Bestelink, et al., Adv. Itell. Sys., 3, 2000199 (2021). Figure 1

A Review on VCII Applications in Signal Conditioning for Sensors and Bioelectrical Signals: New Opportunities.

This study reviews second-generation voltage conveyor (VCII)-based read-out circuits for sensors and bioelectrical signal conditioning from existing literature. VCII is the dual circuit of a second-generation current conveyor (CCII), which provides the possibility of processing signals in the current domain while providing output signals in the voltage form. The scope of this paper is to discuss the benefits and opportunities of new VCII-based read-out circuits over traditional ones and bioelectrical signals. The achieved main benefits compared to conventional circuits are the simpler read-out circuits, producing an output signal in a voltage form that can be directly used, improved accuracy, possibility of gain adjustment using a single grounded resistor, and the possibility of connecting several SiPM sensors to the readout circuit. The circuits studied in this paper include VCII- based read-out circuits suitable for all types of sensors configured in the current-mode Wheatstone bridge (CMWB) topology, the VCII-based read-out circuits solutions reported for silicon photomultiplier, spiral-shaped ultrasonic PVDF and differential capacitive sensors, and, finally, a simple readout circuitry for sensing bioelectrical signals. There are still not many VCII-based readout circuits, and we hope that the outcome of this study will enhance this area of research and inspire new ideas.

Transfer Function-Based Characterization of the Honey Bee Olfactory System: From Biology to Electronic Circuits

We exemplify an interdisciplinary approach wherein a mesoscopic-scale functional model of a biological system is derived from time-series recordings, yielding transfer functions that can be used to design analog electronic circuits. Namely, sensory processing in the honey bee, a universal model for studying olfaction, is considered. Existing studies have focused on its antennal lobe, wherein only the responses of its functional units, known as glomeruli, have been accessible. Here, high temporal resolution calcium imaging is deployed to track the dynamics of odor-evoked activity beyond this processing stage. The responses in the somata outside of the antennal lobe are recorded, showing for the first time how the glomerular signals are transformed before entering the higher brain centers. A transfer function approach is applied to capture as a “gray box model” the remarkably heterogeneous signal transformations between odor input and glomerular response, and between glomerular signals and somata activity. The somata are tentatively mapped to the glomeruli via Granger causality, while machine learning classification and clustering allow grouping common properties regarding response amplitudes and temporal profiles. The obtained low-order transfer functions display time- and frequency-domain input-output properties closely similar to the biological system. Because transfer functions have universal applicability, once they have been determined, it is readily possible to design corresponding analog electronic circuits, with possible future applications in sensor signal conditioning. To exemplify this, examples based on resistor-capacitor (RC) networks and operational amplifiers are physically built and confirmed to generate responses highly correlated to the initial biological recordings.

A Highly Accurate, Polynomial-Based Digital Temperature Compensation for Piezoresistive Pressure Sensor in 180 nm CMOS Technology.

Recently, piezoresistive-type (PRT) pressure sensors have been gaining attention in variety of applications due to their simplicity, low cost, miniature size and ruggedness. The electrical behavior of a pressure sensor is highly dependent on the temperature gradient which seriously degrades its reliability and reduces measurement accuracy. In this paper, polynomial-based adaptive digital temperature compensation is presented for automotive piezoresistive pressure sensor applications. The non-linear temperature dependency of a pressure sensor is accurately compensated for by incorporating opposite characteristics of the pressure sensor as a function of temperature. The compensation polynomial is fully implemented in a digital system and a scaling technique is introduced to enhance its accuracy. The resource sharing technique is adopted for minimizing controller area and power consumption. The negative temperature coefficient (NTC) instead of proportional to absolute temperature (PTAT) or complementary to absolute temperature (CTAT) is used as the temperature-sensing element since it offers the best temperature characteristics for grade 0 ambient temperature operating range according to the automotive electronics council (AEC) test qualification ACE-Q100. The shared structure approach uses an existing analog signal conditioning path, composed of a programmable gain amplifier (PGA) and an analog-to-digital converter (ADC). For improving the accuracy over wide range of temperature, a high-resolution sigma-delta ADC is integrated. The measured temperature compensation accuracy is within ±0.068% with full scale when temperature varies from −40 °C to 150 °C according to ACE-Q100. It takes 37 µs to compute the temperature compensation with a clock frequency of 10 MHz. The proposed technique is integrated in an automotive pressure sensor signal conditioning chip using a 180 nm complementary metal–oxide–semiconductor (CMOS) process.

Wireless Power Transfer Based Non-Destructive Evaluation of Cracks in Aluminum Material

Sensor design and signal conditioning of eddy-current testing are essential research areas for quantitative testing and evaluation. However, crack quantification relies on the variations of sensing mechanism and signal amplitude, which is susceptible to noise under different interferences, thus providing a limited number of features for evaluation. Therefore, this paper proposes a new concept of wireless power transfer (WPT)-based eddy-current testing and evaluation technique for the first time. The novelty of this technique is the introduction of multiple resonance frequencies as features for crack detection and characterization. Multiple resonances allow the selection of specific features for the best sample and crack characteristics. The experimental results from the artificial slots in two different aluminum samples were analyzed based on resonance points and shape of the response features. The results demonstrate that each crack width along the scan axis is proportional to the width of the two sides around it where eddy-current density is highest. Also, from the crack depth quantification, different feature extractions are compared. The results also showed that the smaller the depth of the crack, the higher the frequency feature and lower the amplitude feature.

IoT Network and Sensor Signal Conditioning for Meteorological Data and Photovoltaic Module Temperature Monitoring

The present paper describes the design, development, implementation and validation of an Internet of Things (IoT) network with sensors signal conditioning circuits for monitoring decentralized photovoltaic (PV) plants. The system intends to reduce costs of commercial dataloggers and sensing modules which require control and data storage using proprietary software. We applied our IoT monitoring network in three PV plants installed in Fortaleza and Maracanau cities, Brazil, and in Cologne, Germany. The applied embedded solutions (namely, ESP 8266 and ESP 32) are based on free software and hardware and communicate with a Cloud server via Wi-Fi. A website, called Web Monitor, was developed in PHP for online and real-time data consultation in form of charts. The main objective of the proposal is to measure PV module temperature, providing data for the analysis of PV module’s efficiency and for fault detection in case of PV cells overheating. Solar irradiance, ambient temperature, relative air humidity and wind speed are also monitored, getting more data to analyze the effect of meteorological parameters on the PV module’s performance. The proposed system was designed in compliance with IEC 61724:1998 standard and the obtained charts are discussed in the results section considering different periods of the year. Finally, we validate the proposed temperature conditioning system with a commercial piece of equipment and a correlation of 0.9999 was achieved.

Signal conditioning and processing for metallic Hall sensors

Two electronics prototypes for the ITER outer vessel steady-state magnetic field Hall sensors based on a lock-in signal processing and current spinning technique were developed. The prototypes, the first using a rectangular lock-in signal processing with sensor offset cancellation and the second employing advanced lock-in signal processing with sensor and electronics offset cancellation, were compared with a DC technique and commercial lock-in amplifier. The influence of long interconnection cables, white noise, and interfering planar Hall effect to a measurement accuracy was evaluated. The planar Hall voltage suppression by the current spinning technique was investigated. Whilst the rectangular lock-in amplifier prototype failed to meet the ITER accuracy requirement, the advanced lock-in amplifier prototype demonstrated required functionality and accuracy.

A Sensor Signal Amplifier Resilient to EMI

The rising level of electromagnetic pollution recorded in recent years represents a serious threat to the reliability of electronic devices and systems, which our life is plenty of. Besides corrupting nominal signals, electromagnetic interference (EMI) collected by interconnects can drive active nonlinear devices, which integrated circuits are made of, out of their nominal operating region and this usually results in distortion of the signals. The most harmful effect of such a process is the generation of the baseband intermodulation products, i.e., demodulated EMI that can be distinguished from nominal signals unlikely. This point is addressed in the first part of this paper where the expression of the offset induced by the radio frequency interference in MOS differential pair is derived then used to show the effect of EMI in feedback operational amplifiers. Some techniques to obtain higher immunity levels are also presented. The second part of this paper focuses on low-offset low-noise amplifiers of common use in sensor signal conditioning circuits that usually show high susceptibility to EMI. Aiming to address this issue, a new technique based on the dynamic cancelation of EMI-induced errors is presented, and evidences of its effectiveness are provided showing simulation and measurement results.

Implementation of IoT based Railway Calamity Avoidance System using Cloud Computing Technology

Objectives: Cloud computing and Internet of Things (IoT) are two different emerging technologies that become part of our life. Their adaption and usages are expected to be more and more effective. Railways are providing Eco-Friendly transport system for the mankind. Methods: In this paper we proposed and implemented IoT based cloud computing model using RaspberryPi2.0, LM393 sensor signal conditioning units, Piezo electric buzzer components. Our working model was to integrate with cloud environment by using Linux RTOS, python language and 'smartliving.io' IoT platform via internet using WIFI. In cloud we are providing data of the railway authorities. If any track was damaged in certain point our system detects and transfer that message to cloud, then the cloud automatically sent SMS for concern railway authorities' mobiles. Findings: The railway system use sensors to improve rail transport safety and integrate with local (nearby) stations using wired network. In this scenario, we have two major problems in case of misshaping. First, the concerned railway local authorities doesn't have powers to take their own decisions they were intimate to higher authorities on the situation .It is a long time process to take the decision most of the time it will be late to receive the information. Second, in wired network it is a problem with climatic conditions and vulnerabilities, it has a limitation for integrating number of sensors to current system. Improvements: This system was successful tested and results are evaluated. In our system continuously monitors the status of track and updates it time to time into cloud by IoT platform using RaspberryPi.

Two-step Calibration of Sensor Signal Conditioners

Introduction Mixed-signal integrated circuits (ICs) for sensor signal conditioning are widely used today in sensor applications such as pressure, temperature and position monitoring. In these signal conditioners, the conditioning of the output signal from the sense element is performed with mixed-signal circuits, which are a combination of analog and digital circuits. Moreover, the actual conditioning of the sense-element signals is implemented in the digital domain. The conditioned signal is the output of the sensor signal conditioner. The sensor output is transmitted to a control or monitoring system either in analog or digital form. If an analog form of transmission is used, the processed digital signal must be converted back to analog form. This article examines the calibration of sensor signalconditioning algorithms implemented in signal conditioners that transmit data in analog form. Note that sensor calibration includes the sense-element non-idealities as well as signal-conditioner non-idealities, such as offset and gain errors. The calibration scheme will take care of analog signal-chain errors of the analog circuit that are in front and back of the digital circuits.

Biomimetic Signal Conditioning and Light Adaptation for Compound Vision Sensors

Previous research efforts in mimicking the compound eye of Musca domestica, the common house fly, in hardware have primarily been focused on optical designs to achieve the fast, analog, parallel processing, and motion hyperacuity properties of the biological system. While these optical platforms have shown promising results, nearly all proposed advantages of utilizing a fly-inspired sensor have been discovered through the use of software simulation with very little or no effort being made to validate these simulations using the actual fly-inspired optics. The work presented in this paper advances the frontier of compound vision research by mimicking the core processing systems of the fly's intermediate neural layer structure (the lamina) in hardware. The hardware designs were kept as biomimetic as possible, and the unique motion hyperacuity characteristic of Musca's visual system was preserved in each circuit design. It will be shown that an effective light adaptation system can be designed that is both analog and parallel by directly mimicking the fly's visual system. The proof-of-concept designs presented in this paper are an important first step in turning the novel compound optical designs of the past decade into useful sensors that can function in dynamic real-world environments.

Quench Detection of SST-1 TF Coils by Helium Flow and Pressure Measurement

Superconducting magnets of Steady-state Superconducting Tokamak-1 (SST-1) are cooled by Supercritical helium at 4.5 K and 0.4 MPa. Two types of Venturi meters (VM) are being used for measuring helium mass flow rates in these magnets. Signal conditioning for temperature, absolute pressure and differential pressure sensors and a suitable data acquisition system has also been developed for these flow meters. These flow meters were extensively qualified during individual coil test campaigns of SST-1 TF coils. Mass flow and pressure signal behavior during quench events of TF coil tests were analyzed and a quench detection system using these signals has been proposed for TF coils. This secondary quench detection methodology and its hardware development are discussed in this paper. This paper also describes the VM design, fabrication, installation and the flow measurement system.

효율적인 공기압축기 운영을 위한 이상진단모델 연구

Most systems used in industrial sites, actually have non-linearity and uncertainty. Therefore there are a lot of difficulties in evaluating conditions of these systems. Generally, the quantitative analysis and expression are found hard because the general public cannot easily make an accurate interpretation on the systems. Thus development of a system that utilizes an expertise from skilled analysts is required. In this research, a real-time sensor signal conditioning system and Fuzzy-expert system have been separately set up into an inference algorithm. So that it ensures a fast, accurate, objective and quantitative operational condition value provided to the manager. Therefore, FE_AFCDM is suggested in this literature, as an effective system for diagnosing the problems related to the air compressor. It can quantify the uncertain and absurd condition to operate the air compressor facilities safely and financially.

A comprehensive review of sensors and instrumentation methods in devices for musical expression.

Digital Musical Instruments (DMIs) are musical instruments typically composed of a control surface where user interaction is measured by sensors whose values are mapped to sound synthesis algorithms. These instruments have gained interest among skilled musicians and performers in the last decades leading to artistic practices including musical performance, interactive installations and dance. The creation of DMIs typically involves several areas, among them: arts, design and engineering. The balance between these areas is an essential task in DMI design so that the resulting instruments are aesthetically appealing, robust, and allow responsive, accurate and repeatable sensing. In this paper, we review the use of sensors in the DMI community as manifested in the proceedings of the International Conference on New Interfaces for Musical Expression (NIME 2009–2013). Focusing on the sensor technologies and signal conditioning techniques used by the NIME community. Although it has been claimed that specifications for artistic tools are harder than those for military applications, this study raises a paradox showing that in most of the cases, DMIs are based on a few basic sensors types and unsophisticated engineering solutions, not taking advantage of more advanced sensing, instrumentation and signal processing techniques that could dramatically improve their response. We aim to raise awareness of limitations of any engineering solution and to assert the benefits of advanced electronics instrumentation design in DMIs. For this, we propose the use of specialized sensors such as strain gages, advanced conditioning circuits and signal processing tools such as sensor fusion. We believe that careful electronic instrumentation design may lead to more responsive instruments.

Design and Assembly of High Temperature Distributed Aero-engine Control System Demonstrator

This paper covers the development of a distributed high temperature electronics demonstrator for integration with sensor elements to provide digital outputs that can be used by the FADEC (Full Authority Digital Electronic Control) system or the EHMS (Engine Health Monitoring System) on an aircraft engine. This distributed electronics demonstrator eliminates the need for the FADEC or EHMS to process the sensor signal, which will assist in making the overall system more accurate and efficient in processing only digital signals. This will offer weight savings in cables, harnesses and connector pin reduction. The design concept was to take the output from several on-engine sensors, carry out the signal conditioning, multiplexing, analogue to digital conversion and data transmission through a serial data bus. The unit has to meet the environmental requirements of DO-160 with the need to operate at 200°C, with short term operation at temperatures up to 250°C. The work undertaken has been to design an ASIC based on 1.0μm Silicon on Insulator (SOI) device technology incorporating sensor signal conditioning electronics for sensors including resistance temperature probes, strain gauges, thermocouples, torque and frequency inputs. The ASIC contains analogue multiplexers, temperature stable voltage band-gap reference and bias circuits, ADC, BIST, core logic, DIN inputs and two parallel ARINC 429 serial databuses. The ASIC was tested and showed to be functional up to a maximum temperature of 275°C. The ASIC has been integrated with other high temperature components including voltage regulators, a crystal oscillator, precision resistors, silicon capacitors within a hermetic hybrid package. The hybrid circuit has been assembled within a stainless steel enclosure with high temperature connectors. The high temperature electronics demonstrator has been shown to operate from −40°C to +250°C. This work has been carried out under the EU Clean Sky HIGHTECS project with the Project being led by Turbomeca (Fr) and carried out by GE Aviation Systems (UK), GE Research – Munich (D) and Oxford University (UK).

Trends in Automotive Packaging

The long-term trend in automobiles has been increasing electronics content over time. This trend is expected to continue and drives diverse functional, form factor, and reliability requirements. These requirements, in turn, are leading to changes in the package types selected and the performance specifications of the packages used for automotive electronics. Several examples will be given. This abstract covers the development of a distributed high temperature electronics demonstrator for integration with sensor elements to provide digital outputs that can be used by the FADEC (Full Authority Digital Electronic Control) system or the EHMS (Engine Health Monitoring System) on an aircraft engine. This distributed electronics demonstrator eliminates the need for the FADEC or EHMS to process the sensor signal, which will assist in making the overall system more accurate and efficient in processing only digital signals. This will offer weight savings in cables, harnesses and connector pin reduction. The design concept was to take the output from several on-engine sensors, carry out the signal conditioning, multiplexing, analogue to digital conversion and data transmission through a serial data bus. The unit has to meet the environmental requirements of DO-160 with the need to operate at 200°C, with short term operation at temperatures up to 250°C. The work undertaken has been to design an ASIC based on 1.0 μm Silicon on Insulator (SOI) device technology incorporating sensor signal conditioning electronics for sensors including resistance temperature probes, strain gauges, thermocouples, torque and frequency inputs. The ASIC contains analogue multiplexers, temperature stable voltage band-gap reference and bias circuits, ADC, BIST, core logic, DIN inputs and two parallel ARINC 429 serial databuses. The ASIC was tested and showed to be functional up to a maximum temperature of 275°C. The ASIC has been integrated with other high temperature components including voltage regulators, a crystal oscillator, precision resistors, silicon capacitors within a hermetic hybrid package. The hybrid circuit has been assembled within a stainless steel enclosure with high temperature connectors. The high temperature electronics demonstrator has been demonstrated operating from −40°C to +250°C. This work has been carried out under the EU Clean Sky HIGHTECS project with the Project being led by Turbomeca (Fr) and carried out by GE Aviation Systems (UK), GE Research – Munich (D) and Oxford University (UK).

Passive Source Localization Using Compressively Sensed Towed Array

The objective of this work is to estimate the sparse angular power spectrum using a towed acoustic pressure sensor (APS) array. In a passive towed array sonar, any reduction in the analog sensor signal conditioning receiver hardware housed inside the array tube, significantly improves the signal integrity and hence the localization performance. In this paper, a novel sparse acoustic pressure sensor (SAPS) array architecture is proposed to estimate the direction of arrival (DOA) of multiple acoustic sources. Bearing localization is effectively achieved by customizing the Capons spatial filter algorithm to suit the SAPS array architecture. Apart from the Monte Carlo simulations, the acoustic performance of the SAPS array with compressively sensed minimum variance distortionless response (CS-MVDR) filter is demonstrated using a real passive towed array data. The proposed sparse towed array architecture promises a significant reduction in the analog signal acquisition receiver hardware, transmission data rate, number of snapshots and software complexity. Defence Science Journal, 2013, 63(6), pp.630 -635 , DOI:http://dx.doi.org/10.14429/dsj.63.5765

Sensor less Wash Fluid Detection in Automotive Application

The proposed paper describes the hardware and software method used for detection of wash fluid level in water tank used in automotive; thereby eliminating the need for sensor (Reed type switch mounted on washer bottle) for low wash fluid detection. Wash motor is used for water spray on windscreen during wash and wipe operation. The proposed system makes use of hardware circuit used to drive the wash motor usually of DC (Direct current) type and a feedback circuitry to read back the current consumed by motor during particular wash operation. This hardware system is coupled with software algorithm such that during IGNITION ON instance wash motor will be turned on such as to get motor current readings to determine amount of load operated by motor which is related to wash fluid inside the washer bottle. Motor operation is optimized so as to avoid water spray causing nuisance to user. It also eliminates the cost of the sensor, wiring harness and related signal conditioning circuitry used for sensor data processing. The proposed invention does not suffer from mundane sensor faults such as short to battery / ground, sensor open wire output, variation due to vibration and wear/tear. Language: en

VIBRATION AND CONDITION MONITORING SYSTEM AND THE PARTS THEREOF

A vibration and condition monitoring system with true digital signal processing based design, with very limited analog based general signal conditioning and integrated specific sensor conditioning and sensor power supply options. The device supports direct connection of eddy current probe systems to the module, due to a built-in driver and linearization functionality. Linearization and compensation of a specific eddy current probe/cable system is done by measuring its far/infinite gap response. This response is then according to the invention recalculated into a linearization curve/transfer function. Specific sensor signal conditioning is not dependent on hardware, but only on embedded software (firmware). There is full sensor input support in an I.S. environment. Not only the common sensor input types from accelerometer, velocity sensor or eddy current probe system for both vibration and/or speed measurements.