Abstract:Aiming at the current problems of limited stability and accuracy and high complexity of each solution in non-contact vital signs measurement, a non-contact vital signs measurement method based on matched filtering is designed to achieve low computational complexity and maintain optimality estimation. Five samples are tested in an office environment, and the results show the effectiveness of the proposed method to reduce the vital sign measurement errors due to people′s body movements in real environments. As an example, for sample 4, the variance of heart rate decreases from 2 825 to 82 in the smoothness design, and the root mean square error of heart rate decreases from 16 to 4 in the accuracy tracking calibration design. Clinical experiments are further compared with the current medical reference standards, and the results show that the respiratory rate error is within 1 bpm, while the heart rate measurements are better, which makes it potentially useful.

Abstract:In order to solve the problem of limited field of view during ship berthing and achieve the visualization of berthing distance, a berthing distance perception method based on UAV vision is proposed. First, the UAV is used to collect the berthing video of the ship, and the EMA mechanism is added on the basis of the YOLOv8 segmentation model to achieve the fine segmentation of the ship edges. Next, the berth line is extracted by the regional growth algorithm and the Hough line detection. Finally, the closest distance calculation model is used to convert ships and berths into three-dimensional world coordinate system, and the closest distance between ships and berths is searched. The experimental results show that the accuracy of the algorithm after adding the EMA attention mechanism can reach 92.3% of the segmentation accuracy, and the error of the closest distance between the ship and the berth is less than 0.1 m. This method can not only monitor the environment around the berthing ship, but also achieve the visualization of the distance between the ship and the berth, which has a good application prospect in berthing operation.

Abstract:In order to improve the working efficiency of special equipment testing workers to measure the flexible value under the main beam of the crane, ensure the measurement accuracy and realize the intelligent processing of measurement data, a measurement method based on horizontal laser and photoelectric sensor is proposed, and the principle prototype of the measuring system is designed. The measuring system transforms the arch value of the crane into the height difference of horizontal laser irradiation on the photoelectric sensor array and improves the measurement resolution by the arrangement of the horizontal beam; ensures the horizontal illumination by the focus instead of the horizontal laser in the result with the function of LoRa and 5G wireless communication technology. In the field of a crane girder detection, the system prototype designed in this paper and the traditional theodolite method contrast measurement experiment, the results show that the measurement method and this paper designed the system prototype compared with the traditional theodolite method, the measurement error of each point are less than 0.6 mm, in the experiment, and the total measurement time reduced by about 70%, ensure the measurement accuracy and reliability, significantly improve the measurement efficiency, implements the measurement data real-time upload to the cloud, improve the intelligent degree of the detection work.

Abstract:To enhance the stability of angle measurement methods based on single-vision techniques, which are susceptible to random disturbances from environmental or systemic sources, we propose a dual-viewpoint visual angle measurement method based on complex-valued neural networks. Feature extraction is conducted manually, followed by an assessment of the features’ relevance and monotonicity with respect to angles to facilitate feature selection. To address the significant numerical discrepancy between the 0° and 360° labels, which impacts training outcomes, angles are represented using Euler′s formula. This representation facilitates the construction of a complex-valued neural network with both complex inputs and outputs for angle computation. Experimental results demonstrate a significant improvement in measurement accuracy; the proposed method reduces the mean error by 0.322° and the root mean square error by 0.64° compared to methods based on deep neural networks using a single viewpoint, maintaining high performance across various environmental test sets. By leveraging the robustness against environmental disturbances provided by dual viewpoints and the strong fitting capabilities of complex-valued neural networks for angle labels, this model enhances the accuracy and stability of radial visual angle measurements while adhering to the constraints and stability of mathematical models.

Abstract:With the rapid development of the integrated circuit industry, higher requirements are put forward for integrated circuit testing, and the Precision Measurement Unit is the core unit for integrated circuit DC parameter testing. A PMU circuit for integrated circuit testing is designed in this paper, which uses a Field-Programmable Gate Array to control the DAC module to apply voltage excitation. The excitation signal after the PI regulator and power amplification is applied to the Device Under Test through the resistor matching network, Then, the ADC module reads back the test response data to realize the parameter testing functions such as applying voltage to measure current and applying current to measure voltage. The designed PMU circuit has the advantages of wide test range and high measurement accuracy, with an applied or measured voltage range of -10 V to +15 V and a maximum current of ±1.838 A. The system performance in different test modes was calibrated and functionally verified with high-precision resistive loads, and the experimental results show that the system calibrated test error is better than 0.05%, which is able to meet the requirements of DC parameter testing of general-purpose integrated circuits.

Abstract:An analog front-end circuit for multi-meteorological sensors which mainly includes LDO, programmable gain amplifier, SAR ADC, and humidity measurement circuit was designed. The programmable gain amplifier uses all-difference rail to orbit as the main structure to suppress the noise, and the continuous-time Auto-Zero calibration technology is adopted to reduce its input imbalance voltage. For the 14-bit SAR ADC, in order to reduce the average power consumption and area of CDAC, a segmented differential DAC capacitor array based on the VCM-based switching strategy was designed. Finally, based on the principle of the relationship between the capacitance value of the humidity sensor and the frequency of the rectangular wave, a humidity measurement circuit was designed. The frequency error of the humidity measurement circuit is 0.03%. The analog front-end circuit is based on Hua Hong′s 0.18 μm CMOS process, and the circuit design, layout drawing and simulation verification are carried out through Cadence Spectre software. The post-simulation results show that the circuit as a whole can realize the function of amplifying the input analog signal and finally outputting the digital code, its effective number of bit (ENOB) is 11.40 bit, SINAD is 70.37 dB, SNR is 71.05 dB, SFDR is 83.85 dBc, and THD is -78.55 dB.

Abstract:Aiming at the application reliability of the next generation of new electronic nano-devices, the storage-computing 1T1R nano-devices in array actively integrated RNVM with MOSFET based on the 28 nm CMOS process were designed and fabricated, and its comprehensive electrical performances were tested and evaluated in terms of switching ratio(107-8), operating voltage(±1 V), storage windows and so on. The specific reliability experiments were designed and implemented. The results indicated that the unique failure phenomena which did not occur separately in discrete devices truly existed in 1T1R nano-devices in array including the Ion/Ileak degradation (-44.90%/751.64%) of MOSFET in stress and the reverse hard-breakdown of RRAM during cycling tolerance. Taking the microscopic physics mechanism of nano-device into account, the conclusions were summarized that the unique reliability principles triggered by high source-drain voltage and weak gate-control conditions were attributed to the complex micro interaction mechanisms due to its unique structural features and operating modes of 1T1R nano-devices in array. The pertinently specialized test regulation schemes were proposed to improve the reliability of 1T1R nano-devices in array. References for resolving the unique reliability issues caused by the integration of RNVM nanotechnology with logic devices at 28 nm CMOS nodes and below were provided.

Abstract:This article proposes an online identification method for a electro-optical tracking system based on the Zynq platform, addressing the cumbersome and inefficient nature of traditional identification. By designing data acquisition and driver programs for A/D and D/A modules, real-time collection and control are achieved, and running the VxWorks operating system on Zynq platform. The use of FFT technology enables the online measurement of frequency characteristics, and a hybrid improved quantum-behaved particle swarm optimization algorithm with natural selection parameters is employed for system identification. Experimental results demonstrate that this method possesses high-precision frequency characteristic measurement and accurate system identification capabilities, providing effective means for real-time control and optimization of electrooptical tracking systems.

Abstract:The UAV passive positioning system can realize the bistatic passive positioning of the target with the help of radio and television signals, and the performance of the signal processing board directly determines the positioning accuracy. In order to adapt to the light UAV platform and ensure the accuracy of positioning measurement, a miniaturized signal processing board is designed in this paper. Firstly, the traditional architecture of the signal processing board is simplified and optimized, and FPGA+AD9467 is used as the overall architecture of signal processing. In order to solve the signal integrity problem caused by the miniaturized design, the Cadence and HFFS simulation software are used to simulate and analyze the signal integrity of the processing board during the whole design process, and the signal integrity of the processing board is ensured from the aspects of reflection, crosstalk, and electromagnetic shielding. In order to improve the signal resolution ability of the processing board, a four-spectrum line difference algorithm based on Blackman window function was designed on the basis of the traditional FFT spectrum measurement. The algorithm is used to test the spectral characteristics of the received signal of the processing board, which reduces the measurement error caused by spectrum leakage and fence effect and improves the measurement accuracy. The SNR is better than 90 dB and the SFDR is better than 75 dB in the 29.5 kHz bandwidth. The test results show that the signal processing ability of the designed miniaturized signal processing board is excellent, which meets the application scenarios of passive positioning of light UAV.

Abstract:For the measurement of seawater low conductivity environments such as salty tide, this paper proposes a single-coil measurement model based on magnetic resonance and eddy current technology. An equivalent coupled circuit model of seawater eddy current applicable to single-coil magnetic resonance is established, and the specific influence of eddy current loss on the circuit parameters is theoretically analyzed. The influence of series and parallel resonance on seawater conductivity measurement is investigated by comparing theory and simulation, and it is proved that the variation of the imaginary part of the voltage of the parallel load is more stable than that of the series resonance. The single-coil seawater conductivity measurement system was built for laboratory tests, and the test results show that the loop resonance has an obvious enhancement effect on seawater eddy currents, the load voltage at resonance varies linearly with the growth of conductivity, and the parallel resonance method is better than the series resonance method in the measurement. The magnetic resonance single-coil model has the feasibility of seawater conductivity measurement and has a good development prospect in the direction of low conductivity, non-contact sensors.