Showing papers on "Inductive sensor published in 2020"

Wearable Device to Monitor Back Movements Using an Inductive Textile Sensor.

Abstract: Low back pain (LBP) is the most common work-related musculoskeletal disorder among healthcare workers and is directly related to long hours of working in twisted/bent postures or with awkward trunk movements. It has already been established that providing relevant feedback helps individuals to maintain better body posture during the activities of daily living. With the goal of preventing LBP through objective monitoring of back posture, this paper proposes a wireless, comfortable, and compact textile-based wearable platform to track trunk movements when the user bends forward. The smart garment developed for this purpose was prototyped with an inductive sensor formed by sewing a copper wire into an elastic fabric in a zigzag pattern. The results of an extensive simulation study showed that this unique design increases the inductance value of the sensor, and, consequently, improves its resolution. Furthermore, experimental evaluation on a healthy participant confirmed that the proposed wearable system with the suggested sensor design can easily detect forward bending movements. The evaluation scenario was then extended to also include twisting and lateral bending of the trunk, and it was observed that the proposed design can successfully discriminate such movements from forward bending of the trunk. Results of the magnetic interference test showed that, most notably, moving a cellphone towards the unworn prototype affects sensor readings, however, manipulating a cellphone, when wearing the prototype, did not affect the capability of the sensor in detecting forward bends. The proposed platform is a promising step toward developing wearable systems to monitor back posture in order to prevent or treat LBP.

Structure and modelling of four-layer screen-returned PCB Rogowski coil with very few turns for high-bandwidth SiC current measurement

Abstract: Accurate measurement of current through a silicon carbide (SiC) device is especially challenging, because of its fast switching speed. Its accompanied current sensor must hence have a high-bandwidth and a high-noise immunity. It must also not interfere with operation of the device. Due to these, the printed-circuit-board (PCB) Rogowski current sensor is particularly suitable, but normally requires many layers. With only four layers, the existing Rogowski coils are not yet capable of shielding ambient voltage and magnetic noises simultaneously. Moreover, their computed and measured self-inductances are usually very different with errors as high as 45% reported in the literature. To resolve these issues, an alternative four-layer screen-returned PCB coil has been presented. The described coil uses very few turns to preserve its high bandwidth at the expense of even tougher determination of its self-inductance. An alternative piecewise modelling method has therefore been proposed for finding its self-inductance, needed for designing its theoretical bandwidth. These, together with a non-inverting integrator, permit current through an SiC device to be measured accurately, as demonstrated experimentally.

Textile‐Based Inductive Soft Strain Sensors for Fast Frequency Movement and Their Application in Wearable Devices Measuring Multiaxial Hip Joint Angles during Running

Abstract: Wearable multiaxes motion tracking with inductive sensors and machine learning is presented. The production, characterization, and use of a modular and size‐adjustable inductive sensor for kinematic motion tracking are introduced. The sensor is highly stable and able to track high‐frequency (>15 Hz) and high strain rates (>450% s−1). Four sensors are used to fabricate a pair of motion capture shorts. A random forest machine learning algorithm is used to predict the sagittal, transverse, and frontal hip joint angle, using the raw signals from sport shorts during running with a cohort of 12 participants against a gold standard optical motion capture system to an accuracy as high as R2 = 0.98 and root mean squared error of 2° in all three planes. Herein, an alternative strain sensor is provided to those typically used (piezoresistive/capacitive) for soft wearable motion capture devices with distinct advantages that can find applications in smart wearable devices, robotics, or direct integration into textiles.

An Inductive Sensor for Two-Dimensional Displacement Measurement.

Abstract: The simultaneous and independent measurements of two-dimensional (2D) displacements are significant for 2D positioning. Here a planar inductive sensor which is based on the principle of electromagnetic induction is proposed. The sensor is composed of a primary coil and a secondary coil. The primary coil consists of an array of planar spiral coils which are arranged as an m × n matrix. The primary coil is supplied with 4 kHz alternating current to generate an array of pulsating magnetic field. The secondary coil contains four spiral coils which are arranged as a 2 × 2 matrix. Thereby, four roads of modulated signals whose amplitudes vary with displacements of the secondary coil along x- and y-axis are induced. An algorithm based on the Coordinate Rotation Digital Computer algorithm is introduced to resolve the planar displacements. The structure and working principle of the sensor are proposed firstly. Then, the finite element analysis of the electromagnetic model and the numerical simulation of the algorithm are given. An experiment has been performed on a sensor prototype and the results show that the proposed scheme is feasible. Measurement error analysis of the sensor has been pursued at the end of the paper.

Non-Destructive Testing of the Longest Span Soil-Steel Bridge in Europe—Field Measurements and FEM Calculations

Abstract: The article describes interdisciplinary and comprehensive non-destructive diagnostic tests of final bridge inspection and acceptance proposed for a soil-steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure short-term response was collected. Periodic diagnostics of bridge deformations was done one year after it was built. Load test design was based on numerical simulations performed by means of finite element method (FEM). In situ measurements were done with the aid of: inductive sensors, optical total station, and terrestrial laser scanner. The results produced by terrestrial laser scanning were used to build a precise image of structure deformation in 3D space during the tests. The accuracy of laser mapping was significantly increased using the information coming from total station and inductive sensors. These have higher accuracy and therefore can be used as reference. Thus, new quality in measurements is introduced. Good correspondence between in situ values and FEM estimations was achieved. Therefore, such a combination of testing methods can be used in non-destructive diagnostics of structures and is an interesting alternative for the standard approach, in which the measurements are done in limited number of points.

Improved magnetic lateral flow assays with optimized nanotags for point-of-use inductive biosensing

Abstract: Lateral flow assays may be used by minimally trained personnel for fast and inexpensive bioanalyses in decentralized non-exigent environments. Their extension to a broader catalog of applications depends on improvements in their quantification and their sensitivity. We report a strategy that combines nanomagnetic tagging of the analyte of interest with radiofrequency inductive sensing, easy to achieve in friendly and portable format. To optimize nanotag performance, we investigated the influences of their magnetic core size and agglomeration. Iron oxide nanoparticles, with sizes from 5 to 23 nm, were synthesized by thermal decomposition and then coated with dimercaptosuccinic acid and functionalized with neutravidin protein. We tested the system by immobilizing biotin in lateral flow membrane strips. When a sample containing the particles flows along the membrane, the biotin captures the neutravidin together with the magnetic nanotags, which are detected by the inductive sensor. The optimal nanotag core size is the critical threshold for superparamagnetic behavior, which maximizes both the initial magnetic permeability and the saturation magnetization. Controlled agglomeration of the nanotags increases the magnetic mass captured in the test line and further amplifies the signal.

A Stretchable Inductor With Integrated Strain Sensing and Wireless Signal Transfer

Abstract: Objective: A soft and stretchable inductive sensor is presented with the ability to wirelessly transmit large strain measurements without the need for directly connected circuitry. Methods: The sensor is fabricated using a scaffold-removal technique to create microfluidic channels within an elastomer sheet (0.07 MPa modulus), which are injected with a non-toxic liquid metal alloy electrode. An analytical model is derived to predict the static inductance of the sensor while being uniaxially stretched and experimental characterisation of the sensor’s dynamic response to axial and biaxial deformation is conducted, as well as wireless measurements within ex-vivo porcine tissue. Results: Experimental validation showed that the sensor’s inductance change is linear with uniaxial and biaxial strains up to twice its original length. Strain-rate dependent hysteresis was negligible during slow deformation ( $ ) and below 10% during more rapid changes in length ( $15\,\,{s}^{-{1}}$ ). For wireless strain sensing, the variation of inductance in the sensor induced an increase in the transmitting voltage from 3.1 V to 5.7 V for strains up to 83%. While implanted within different layers of porcine tissue, the transmitter voltage linearly increased by 750 mV on average under bending deformation. Conclusion: Large stretching (83%) and bending ( $8\,\,{m}^{-{1}}$ ) deformations in the inherently soft sensor can be wirelessly captured, including through biological tissue. Significance: The wireless sensor’s simplified structure, where the antenna and sensor are integrated into a single soft spiral electrode with modulus comparable to biological tissue, means that this novel design shows significant potential for implantable and wearable biomedical devices to monitor dynamic deformation.

An Implantable Wireless Inductive Sensor System Designed to Monitor Prosthesis Motion in Total Joint Replacement Surgery

Abstract: Currently, the most common method for detecting prosthetic implant loosening is imaging. Unfortunately, imaging methods are imprecise in detecting the early signs of implant loosening. This paper describes a new wireless inductive proximity sensor system for detecting early implant loosening. The loosening of the implant is accurately detected by analyzing the electromagnetic field generated by the passive sensors located around the implant. The sensor system was modeled and simulated using COMSOL, and then tested experimentally. The inductive proximity sensor and the metallic implant form a coupled circuit is tuned to oscillate at a designed frequency. The circuit’s integrated controller measures and records specific sensor’s parameters such as resistance and inductance of the sensor that are directly related to the distance between the sensor system and the implant. A prototype has been developed and the results show that the designed proximity sensor is capable of measuring the loosening of the hip implant at $\text{50}\ \mu$ m resolution at distances of less than $\text{8 mm}$ , and of $\text{100}\ \mu$ m resolution at a distance of $\text{15 mm}$ . Furthermore, there is a good correlation between the simulated and experimental results.

Multi-chip synchronization in sensor applications

Abstract: A system may include a plurality of actively-driven inductive sensors and a plurality of control circuits, each control circuit of the plurality of control circuits configured to control operation of a respective set of the actively-driven inductive sensors, each control circuit of the plurality of control circuits communicatively coupled to the other control circuits via a connection configured to distribute synchronization information among the plurality of control circuits. Each of the plurality of control circuits may further be configured to configure a schedule for controlling time-division multiplexed operation of its respective set of actively-driven inductive sensors and control time-division multiplexed operation of its respective set of actively-driven inductive sensors based on the schedule and the synchronization information in order to minimize interference among the plurality of actively-driven inductive sensors.

A novel hybrid serial/parallel multi-frequency measurement method for impedance analysis in eddy current testing.

Abstract: This paper proposes a novel hybrid serial/parallel multi-frequency measurement method for measuring the impedance/inductance of eddy current sensors. Parallel multi-frequency measurement normally has a higher measurement speed, but a lower signal-to-noise ratio (SNR). In contrast, serial multi-frequency (sweeping frequency) has a lower measurement speed, but a higher SNR. The method proposed in this paper can flexibly combine these two features to deliver the desired speed and SNR according to the requirements of a specific application. A system is designed using the proposed method based on a field-programmable gate array. The composite parallel excitation signal is generated by a direct digital synthesis module, and the received multi-frequency data are simultaneously demodulated by a digital I/Q demodulator. The system is applied to measure the impedance of an inductive sensor, and a good agreement between the measurements from a commercial impedance analyzer and the designed system has been found.

Improving the Detection Ability of Inductive Micro-Sensor for Non-Ferromagnetic Wear Debris.

Abstract: The inductive debris sensor has been studied because of its wide application prospects in mechanical health monitoring. In order to ensure a high-precision detection performance, a comprehensive method to improve the detection sensitivity and detection ability of the inductive sensor for non-ferromagnetic metal debris is proposed. Based on the characteristics of the eddy current inside the metal, the change of the coil impedance caused by the metal debris is increased by enhancing the magnetic field strength and selecting the optimal excitation frequency. The impedance detection method involving inductance and resistance parameters is used to improve the detection limit of non-ferromagnetic metal debris. The experimental results verify that the magnetic field in the detection region can be enhanced by adding a silicon steel strip (paramagnetic material) in the central hole of the coil, thereby greatly improving the detection sensitivity of the inductive sensor, and the concentrated distribution of the magnetic field avoids the double-peak signals generated by a single particle. The characteristics of the signal amplitude of non-ferromagnetic debris with excitation frequency are studied. Higher inductance, resistance amplitudes, and signal-to-noise ratio (SNR) can be obtained by using a high-frequency alternating current. Compared with inductance parameter detection, resistance parameter detection can detect smaller non-ferromagnetic debris. Combining the detection results of the inductance and resistance parameters can effectively improve the sensor's ability to detect non-ferromagnetic debris.

Sensor Controlled Defense Purpose Robot for Land Mine Detection

Abstract: This paper present an automated metal detecting rover-robot which can be operated by remote to help in the landmine detection. The objective of this metal detector robot is to identify the landmines in war-affected rehabilitation places. The detection of landmines through this proposed method is free of risk and less human effort. Integration of inductive sensor, video camera and ATUNO microcontroller are used here to discover landmines. The system functions using radio frequency (RF) module for device control and Bluetooth module for communication between operator and robot. While experimenting, this robot shows high metal detection ability which is competent enough to be used in the applications in landmine covered regions.

Axial Movement Sensor Based on Chaotic Oscillator and Planar Coil

Abstract: Axial movement measurements are required in different technical tasks. At distances up to several centimeters, inductive sensors are widely used. However, cheap on-the-shelf sensors are often not suitable due to their low sensitivity. Instead of them, linear potentiometers, inductive sensors with moving cores, linear magnetic encoders or laser systems are used, but these solutions have their own limitations and higher costs. In this paper, we propose an inductive sensor consisting of a planar coil included in a chaotic circuit based on the Cang system. Coil inductance serves as a bifurcation parameter. When the target moves and inductance accordingly changes, the phase volume of system's attractor also changes. Nonlinearity of this system allows obtaining a steeper sensitivity characteristic comparing with a harmonic oscillator. The phase volume can be easily detected using analog means, which results in completely analog sensor design. We show that such a system is able to perform movement measurements with adjustable range and high accuracy.

A Non-Linear Temperature Compensation Model for Improving the Measurement Accuracy of an Inductive Proximity Sensor and Its Application-Specific Integrated Circuit Implementation

Abstract: The non-linear characteristic of a non-contacting Inductive Proximity Sensor (IPS) with the temperature affects the computation accuracy when measuring the target distance in real time. The linear model based method for distance estimation shows a large deviation at a low temperature. Accordingly, this paper presents a non-linear measurement model, which computes the target distance accurately in real time within a wide temperature range from −55 °C to 125 °C. By revisiting the temperature effect on the IPS system, this paper considers the non-linear characteristic of the IPS measurement system due to the change of temperature. The proposed model adopts a non-linear polynomial algorithm rather than the simple linear Look-Up Table (LUT) method, which provides more accurate distance estimation compared to the previous work. The introduced model is fabricated in a 0.18 μm Complementary Metal Oxide Semiconductor (CMOS) process and packaged in a CQFN40. For the most commonly used sensing distance of 4 mm, the computed distance deviation of the Application-Specific Integrated Circuit (ASIC) chips falls within the range of [−0.2,0.2] mm. According to the test results of the ASIC chips, this non-linear temperature compensation model successfully achieves real-time and high-accuracy computation within a wide temperature range with low hardware resource consumption.

Application Research of Vision Sensor in Material Sorting Automation Control System

Abstract: Based on the PLC in the material sorting automation system, the paper builds an automatic material sorting system based on visual sensors. The control system involves various sensor technologies such as photoelectric sensors and vision sensors, mechanical technology, electrical and electronic technology, frequency converter technology, motor drive technology, air pressure control technology, human-machine interface technology, etc., and integrates the application of various technologies in training. On the platform, students can familiarize themselves with the process of detecting, transmitting, and processing the automatic production line and the control process of the system through the practice of this training platform. They can be familiar with the mechatronics technology. The system first detects the metal through the inductive sensor, detects the colour through the photoelectric sensor, and finally detects whether the processing is qualified by the machine vision system, and obtains the target data, and finally controls the robot to realize the sorting action, and completes the storage operation of the stereo warehouse.

Inductive Sensors of Angular Acceleration

Abstract: In the context of globalization of the economy in the Republic of Uzbekistan an important place is given to the automation of production, including the field of railway transport. The article provides the information on system automatic control of the railway transport. It analyzes the automatic control system schemes of train traffic and measurement conditions with the main requirements for angular acceleration sensors. The measurement of motion parameters (displacement, speed, acceleration, sharpness - changes in acceleration and vibration parameters) is discussed in the article, in particular, for the transformation of angular acceleration used in the induction sensor of angular accelerations of the inertial principle of action with advanced functionality.

An Implementation Method for an Inductive Proximity Sensor with an Attenuation Coefficient of 1

Abstract: In order to achieve long-distance measurement, a bridge differential inductance detection circuit is employed; on this basis, an automatic zero adjustment technique for sensors using an integral–proportional-integral controller is proposed in this work to achieve consistent product production and efficient installation and debugging, and the mathematical model of the bridge differential inductance detection circuit is established to effectively design the controller parameters. Furthermore, an implementation method for an inductive proximity sensor with an attenuation coefficient of 1 is also proposed based on the bridge differential inductance detection circuit by querying the proximity distance table in the field-programmable gate array (FPGA) to detect multiple target metal objects at the same inductive distance. Simulation and experimental results show that the proposed method is correct and effective.

Identity recognition device and identity recognition method

Abstract: The invention provides an identity recognition device and an identity recognition method. The identity recognition device comprises a substrate with a groove part. A contact type recognition unit is arranged in the groove part of the base body and can recognize the identity of the user after the designated part of the user makes contact with the contact type recognition unit. An inductive sensor is arranged on the base body and is used for sensing whether a specified part extends into the groove part or not. A driving unit is arranged on the base body and is connected with the inductive sensor. A cleaning unit is arranged on the base body and is connected with the driving unit; and when the inductive sensor senses the designated part, the driving unit drives the cleaning unit to clean thefingers. An identity recognition device can temporarily clean fingers of a user and remove sweat or dust and the like on the surfaces of the fingers, so that the surfaces of the fingers are kept clean, and the recognition accuracy of a system is improved.

Development of Inductive Sensor for Control Gate Opening of an Agricultural Irrigation System

Abstract: The monitoring of water level in the agriculture irrigation channels is essential to control the opening gates of these channels. In this way, WSNs (Wireless Sensor Networks) have high relevance to obtain this kind of data. In this paper, we propose a sensor to measure the depth changes in irrigation channels to control the gates opening. It is connected to an Adafruit Feather HUZZAH based on ESP8266, which allows us to build a mobile edge computing system. The developed sensor is based on two coils. Sinus-wave powers the first one, and the second is induced. The coils are winding over a polyvinyl chloride (PVC) that has high resistance for corrosion and low price. Besides, we use copper wire as a conductive metal. We test two different configurations of coils. P1 has five spires for the powered coil (PC) and ten spires for the induced coil (IC). On the other hand, P2 has 40 spires for the PC and 80 spires for the IC. The two prototypes were coiled in one layer. Then, both sensors are tested using a glass bottle where the water column increased with the target to obtain the information of the depth. In both prototypes, the difference of voltage between the maximum and minimum studied depths is more or less the same, 4.46V for P1 and 4.44V for P2. Nevertheless, during the stabilization test, the P1 showed better adaptation for the turbulences than the P2. The P1 shows an oscillation of 0.48V, where the P2 has a maximum fluctuation of 3.2V.

Counting rectangular objects on conveyors using machine vision

Abstract: Counting the number of objects that are transported on a conveyor belt is frequently encountered in production facilities, airports or post offices. Although most of these tasks may usually be solved by using common photoelectric or inductive sensors, there are cases when objects have to be counted using more complex sensing systems based on machine vision. In this paper, an image-processing algorithm for segmenting, detecting and counting rectangular objects which are being transported on a conveyor belt is presented. The method is specifically designed to detect rectangular objects that can be partly occluded. The application is implemented using OpenCV/C++ library. Two different test scenarios are analyzed in the paper. Experimental results suggest that the proposed method has promising accuracy and it is applicable in real-world applications.

Modelling and Measurement of Magnetically Soft Nanowire Arrays for Sensor Applications.

Abstract: Soft magnetic wires and microwires are currently used for the cores of magnetic sensors. Due to their low demagnetization, they contribute to the high sensitivity and the high spatial resolution of fluxgates, Giant Magnetoimpedance (GMI), and inductive sensors. The arrays of nanowires can be prepared by electrodeposition into predefined pores of a nanoporous polycarbonate membrane. While high coercivity arrays with square loops are convenient for information storage and for bistable sensors such as proximity switches, low coercivity cores are needed for linear sensors. We show that coercivity can be controlled by the geometry of the array: increasing the diameter of nanowires (20 µm in length) from 30 nm to 200 nm reduced the coercivity by a factor of 10, while the corresponding decrease in the apparent permeability was only 5-fold. Finite element simulation of nanowire arrays is important for sensor development, but it is computationally demanding. While an array of 2000 wires can be still modelled in 3D, this is impossible for real arrays containing millions of wires. We have developed an equivalent 2D model, which allows us to solve these large arrays with acceptable accuracy. Using this tool, we have shown that as a core of magnetic sensors, nanowires are efficiently employed only together with microcoils with diameter comparable to the nanowire length.

Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users.

Abstract: Liner-to-socket distance measurement using inductive sensing may be an effective means to continuously monitor socket fit in people using trans-tibial prostheses. A practical limitation, however, is a means to incorporate a thin uniform-thickness layer of conductive or magnetically permeable target material into the wide range of prosthetic liner products that people with limb amputation commonly use. In this paper, a method is presented whereby a 0.50-mm thickness ferrous polymer made from a SEEPS polymer and iron powder that is formed adjacent to a 0.25-mm thick non-ferrous layer of SEEPS polymer is assembled between two sheets of elastic fabric material. Bench testing showed that the fabrication procedure achieved a root-mean-square error in the thickness of this construct of 58 μm, helping to create a consistent calibration result over the entire surface. The original fabric backing of an off-the-shelf prosthetic liner was removed and replaced with the developed construct. When worn in the shoe of an able-bodied participant for 7.5 h per day for 28 days, the sensor well maintained the shape of its calibration curve at the start of wear, but a distance offset (shifting of the y-intercept) was introduced that increased during the initial approximately 12 days of wear. When the distance offset was corrected, for the primary distance range of clinical interest for this application (0.00–5.00 mm), the sensor maintained its calibration within 4.4%. Before being used in clinical application for liner-to-socket distance monitoring, new ferrous liners may need to be pre-worn so as to achieve a consistent distance reference.

A method of reducing the error in determining the angular displacements when using inductive sensors

Abstract: Goal. Representation of a special mathematical software for determining the angular displacements of the rotor of the induction angle sensor – resolver (rotating transformer) for applications in which the speed of the sensor's rotor is close to zero. As well as performing its experimental verification. Methodology. The presented method is based on the determination of the phase shift angle of the output signals of the induction sensor, which is determined by comparing the obtained arrangements of signal values with a circular discrete convolution in order to achieve the most precise approximation of the obtained signal values to cosine and sine. The conversion of orthogonal components to an angle is based on the use of a digital phase detector which is use of a software comparator and inverse trigonometric functions. Results. Based on the obtained results of mathematical modeling and experimental research, the characteristic dependencies of the angle of rotation of the rotor of the induction sensor relative to its stator, the nature of which is linear, were obtained. In addition, the estimation of measurement errors of angular displacements is carried out that occur when defining such angles by the method offered. The obtained results of the computer simulation taking into account the high signal noise, as well as the results of experimental investigations, confirm the high precision of this method and the fact that it can be used in systems where high positioning accuracy is required and the speed of the sensor shaft is close to zero. Originality. This article introduces, for the first time, special mathematical software for a new method of determining the angular displacements of the rotor of an induction sensor, which is based on the determination of the orthogonal components of the signal in combination with the use of a circular discrete convolution in the determination of the phase shift angle of the induction sensor signals. Practical meaning. The proposed method does not require the use of demodulators, counters and quadrant tables associated with conventional methods for determining the phase shift of signals. The presented method can be used to measure the full range of 0-2p angular displacements in real time, is simple and can be easily implemented using digital electronic circuitry.

Optimation of Crawler Speeds Measurement Using Inductive Proximity for Autonomous Combine Harvester

Abstract: This paper proposes an optimal method for measuring the crawler rotational speeds of an autonomous combine harvester by the inductive proximity sensor. It mounts an inductive sensor on each wheel so it can detect the metals and the holes on the crawler drive gear. Detection of metals and holes continuously forming a cycle with a particular frequency. The crawler speed is determined by counting the number of cycles at one second as a frequency. The crawler speeds are proportional to the frequency. However, there is another way of measuring crawler speed by counting the cycle period. This research compares measuring methods for the crawler speeds using frequency and period to determine the optimal method. The results of the experiment show that measuring crawler speeds by periods is more accurate than frequency.

Dual Detector With Transverse Coils

Abstract: The invention relates to a dual detector comprising a detection head having: an inductive sensor which is mounted on the platform (11) and includes a transmitter coil (12) and a separate receiver coil (13), the transmitter coil (12) and the receiver coil (13) each forming a loop, a soil penetrating radar (60) comprising a transmitter antenna (61) and a receiver antenna (62), the transmitter antenna (61) and the receiver antenna (62) each being accommodated in the center of one of the loops of the transmitter and receiver coils (12) (13), the transmitter antenna (61) and the receiver antenna (62) having a maximum thickness (e) of one micron in order to limit interference with the inductive sensor (12).

Emergency brake control circuit based on coupler coupling detection

Abstract: The utility model relates to an emergency brake control circuit based on car coupler coupling detection, which comprises a car coupler state detection circuit and a car coupler state relay which are connected in series with a train power supply loop, and a normally open contact of the car coupler state relay is connected to an emergency brake train line in a cross parallel mode. When the coupler is normally coupled, the inductive proximity sensor located on the coupler knuckle and the central pivot is closed, the coupler state relay is driven, and a normally open contact of the coupler state relay ensures closing of a corresponding node of the emergency brake loop in a cross parallel connection mode. After the coupler is abnormally coupled or accidentally unhooked, the inductive proximitysensors of the couplers of the two adjacent carriages are disconnected at the same time, the coupler state relays of the two vehicles are powered off, and emergency braking is applied. In addition, when the coupler state relay breaks down, normal use of the emergency circuit can be guaranteed by operating the corresponding bypass switch to bypass the fault. According to the utility model, the linkage of accidental unhooking and emergency braking of the coupler can be realized, and the reliability of a circuit is improved.