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The purpose of this paper is to present a novel image‐labeling CMOS sensor for modulated marker detection.

An image scene with multiple objects, each identified by a flashing light‐emitting diode (LED), is captured by the sensor. The LED's frequency is a representation of the object ID‐tag. The sensor detects and labels the objects by identifying the signal frequencies. The processing is performed in‐pixel and, since the object detection task is simplified, power dissipation is reduced. A 64×64 pixel sensor is designed in the 0.6 μm CMOS technology.

Simulation results show successful object identification. At a frame rate of 250 fps the measured power consumption is 11 mW, which is less than those of the previously reported object detection solutions. The application of the presented sensor is shown in several different robotic fields such as unmanned aerial vehicles (UAVs) vision, household robots and industrial robots. It is also explained how the sensor can be used for low‐power localization and position detection of the robot vehicles.

The paper shows that the sensor is a suitable solution for low‐power landmark detection and robot localization.

There is an increasing demand for higher-accuracy dimensional measurements of nano- and micro-structures. Recently, the authors presented a fiber Bragg grating (FBG) sensor-based dynamic nano-coordinate-measuring machine (CMM) probe for true three-dimensional coordinate measurement, in which a specific mechanical structure with several FBG sensors was developed to provide the probe with sensitivity to loading in all directions.

The study presents a three-dimensional sensing and demodulation system based on an improved matched filter design and the time division multiplexing technique that helps solve the problem of multiplex FBG-signals conflicts. In addition, the application of the dynamic mode of the probe system effectively solves the problem presented by the surface interaction forces.

Consequently, this FBG-based vibrating probe system has increased sensitivity to strain, while maintaining smaller contact force. The experiments for testing probe performance show that the prototype yielded a measurement resolution of 13 nm, a repeatability of 50 nm and a vertical measurement force of less than1.5 mN.

The force tests in the horizontal directions are difficult to conduct because both the probe and the dynamometer are only adaptable to vertical use.

Development of the FBG-based dynamic nano-coordinate-measuring machine probe will achieve a new and inexpensive method for higher-accuracy dimensional measurements of nano- and micro-structures, such as micro-electromechanical systems, micro-fluidic chips, inkjet and diesel engine injector nozzles that are in overall dimensions within the micrometer scale.

The study presents a three-dimensional sensing and demodulation system for the vibrating nano-coordinate-measuring machine probe based on FBG sensors. The prototype yielded a measurement resolution of 13 nm, a repeatability of 50 nm and a vertical measurement force of less than1.5 mN.

The purpose of this paper is to present the latest sensing structure designs and principles of information detection of fiber Bragg grating (FBG) displacement sensors. Research advance and the future work in this field have been described, with the background that displacement and deformation measurements are universal and crucial for structural health monitoring.

This paper analyzes and summarizes the existing FBG displacement sensing technologies from two aspects principle of information detection (wavelength detection, spectral bandwidth detection, light intensity detection, among others) and principle of the sensing elastomer structure design (cantilever beam type, spring type, elastic ring type and other composite structures).

The current research on developing FBG displacement sensors is mainly focused on the sensing method, the construction and design of the elastic structure and the design of new information detection method. The authors hypothesize that the following research trends will be strengthened in future: temperature compensation technology for FBG displacement sensors based on wavelength detection; a study of more diverse elastic structures; and fiber gratings manufactured with special fibers will greatly improve the performance of sensors.

The latest sensing structure designs and principles of information detection of FBG displacement sensors have been proposed, which could provide important reference for research group.

This paper aims to put forward a nonlinear vibration method for crack detection based on fiber Bragg grating (FBG), which is used to receive the waves in the plate.

First of all, measuring principle of nonlinear vibration technique and FBG sensing principle are introduced. Then nonlinear signal spectrum is analyzed to reveal various models of nonlinear vibration, and modal analysis of the plate structure is performed to lay the foundation for the later experiment. This approach is the cross-modulation effect from a persistent excitation to the receipt signal.

The experimental system is built and its results are in agreement with theoretical analysis, and show that this nonlinear vibration method based on FBG sensor is sensitive to crack damage.

Taking the board structure as the object, a new attempt by nonlinear vibration detection with FBG sensor has been investigated.

The world’s first time‐of‐flight (TOF) 3D range camera without moving parts, based on a custom solid‐state imaging device is described in this article. With the single exception of the smart‐pixel array, only electronic and optical standard components are used. The range camera does not need any mechanically scanning parts. It acquires 10 range images per second and achieves a resolution of a few centimeters over a distance range of 10‐20 meters for non‐cooperative targets. The illumination source consists of 160 LEDs, modulated at 20MHz, with a total optical power of about 800mW. The description of the smart pixel’s working principle and the presentation of our first 3D measurements are completed with a discussion of the theoretical limitations and a comparison with the system performance.

The purpose of this paper is to introduce an algorithm based only on local extreme analysis of a time sequence to further the detection and diagnosis of inter-turn short circuits and unbalanced voltage supply using vibration signals.

The upper and lower extreme envelopes from a modulated and oscillatory time sequence present a particular characteristic being of, theoretically, symmetrical versions with regard to amplitude reflection around the time axis. Thus, one may say that they carry the same characteristics in terms of waveforms and, consequently, frequency content. These envelopes can easily be built by an interpolation process of the local extremes, maximums and minimums, from the original time sequence. Similar to modulator signals, they contain more detailed and useful information about the required electrical fault frequencies.

Results show the efficiency of the proposed algorithm and its relevance to detecting and diagnosing faults in induction motors with the advantage of being a technique that is easy to implement in any computational code.

A laboratory investigation carried out through an experimental setup for the study of faults, mainly related to the stator winding inter-turn short circuit and voltage phase unbalance, is presented.

The main contribution of the work is the presentation of an alternative tool to demodulate signals which may be used in real applications like the detection of faults in three-phase induction machines.

The purpose of this paper is to study the effect of diode power detector modelling on six-port communication receiver performance.

Based on proposed and conventional squared diode model, six-port receiver’s demodulation and its error vector magnitude (EVM) performance due to hardware impairments are studied. Through considering both the models, the accuracy of proposed power detector model is compared to the squared model, and then both results are validated with envelope simulation (ENV) in advanced design system (ADS).

Comparing the numerical results with envelope simulation results proved that the proposed model is much more accurate than the conventional squared model for a wide range of input power levels.

Studying the receiver’s performance numerically, by considering the new proposed analytical approach for diode power detectors which is more accurate than the conventional squared model.

Wireless sensor networks (WSN), as a solution for buried water pipe monitoring, face a new set of challenges compared to traditional application for above-ground infrastructure monitoring. One of the main challenges for underground WSN deployment is the limited range (less than 3 m) at which reliable wireless underground communication can be achieved using radio signal propagation through the soil. To overcome this challenge, the purpose of this paper is to investigate a new approach for wireless underground communication using acoustic signal propagation along a buried water pipe.

An acoustic communication system was developed based on the requirements of low cost (tens of pounds at most), low power supply capacity (in the order of 1 W-h) and miniature (centimetre scale) size for a wireless communication node. The developed system was further tested along a buried steel pipe in poorly graded SAND and a buried medium density polyethylene (MDPE) pipe in well graded SAND.

With predicted acoustic attenuation of 1.3 dB/m and 2.1 dB/m along the buried steel and MDPE pipes, respectively, reliable acoustic communication is possible up to 17 m for the buried steel pipe and 11 m for the buried MDPE pipe.

Although an important first step, more research is needed to validate the acoustic communication system along a wider water distribution pipe network.

This paper shows the possibility of achieving reliable wireless underground communication along a buried water pipe (especially non-metallic material ones) using low-frequency acoustic propagation along the pipe wall.

The Fabry-Perot sapphire optical fiber sensor is an excellent choice for high-temperature sensing in civil and military fields, such as oil exploitation, engine and turbine. The purpose of this paper is to study the high-reflective film system withstanding high temperature in Fabry-Perot sapphire optical fiber high-temperature sensor. To improve the performance of the sensor and reduce the difficulty of signal acquisition, one of the key ways is to enhance the normalized light intensity of F-P sensor, which can be achieved by coating the high-reflective film system on the fiber end.

The high-reflective film system can be achieved by a multilayer film with alternating ZrO₂ and Al₂O₃ film layers whose refractive indexes are different. In addition, the optimum film alternating sequences and the influence of the number of film layers, incident angle and temperature should be obtained by numerical analysis.

With the increase of the number of film layers, the reflectivity rises gradually and the change trend is more and more gentle. A minimum of the spectral reflectivity will occur at a certain incident angle depending on the design of the periodic multilayer system. Temperature affects the reflectivity of high-reflective film system. The normalized light intensity of the F-P sensor coated with high-reflective film system enhances greatly which is helpful to the signal demodulation. The temperature response of the F-P sensor is mainly determined by the characteristics of the F-P cavity.

Higher reflectivity, lower cost and easy signal acquisition are the most important features of the introduced high-reflective film system for the Fabry-Perot sapphire optical fiber high-temperature sensor.

The purpose of this paper is to propose an improved reconfigurable zero‐IF RF receiver with anti‐interference improvement used in dynamic spectrum resource sharing system at UHF band based on tunable filter array computation. Measured results show that the anti‐interference competence of improved zero‐IF RF receiver is enhanced greatly by employing two tunable filter arrays.

The anti‐interference reconfigurable zero‐IF RF receiver is based on fully differential I/Q demodulation structure and employs two same tunable filter arrays to meet the requirement on adjacent channel suppression imposed by systems coexisting. The performance requirement of each filter in tunable filter arrays is computed and derived according to the needs of anti‐interference.

The anti‐interference competence of zero‐IF RF receiver could be enhanced greatly by employing two tunable filter arrays.

The paper provides a method to design zero‐IF RF receivers with anti‐interference competence used in dynamic spectrum resource sharing systems.