High-speed Requirements Research Articles

A Novel Parallel Architecture for Template Matching based on Zero-Mean Normalized Cross-Correlation

Template matching based on zero-mean normalized cross-correlation measure (ZNCC) has been widely used in a broad range of image processing applications. To meet the requirements for high processing speed, small size, and variable image size in automatic target recognition systems, a novel field-programmable gate array (FPGA)-based parallel architecture is presented in this paper for the ZNCC computation. The proposed architecture employs two groups of RAM blocks, one of which is used for the multiply-accumulate operations of the real and the reference images and the other for data rearrangement of the reference image, and their functions are switched through 2-input multiplexers when searching at the next row. Moreover, the sum of the pixels in the searching area of the real image is computed through serially accumulating the differences between the new column in the current searching area and the old column in the last searching area using one dual-port RAM. Simultaneously, the sum of the squares of the pixels is calculated in the same way. Using the Altera Stratix II FPGA chip (EP2S90F780I4) as the target device, the compilation results with Quartus II show that compared with the traditional architecture, the synthesis logic utilization decreases from 63% to 35% and the usage of DSP blocks decreases from 59% to 39%, while the memory bits only increase by 8% and the usage of other resources is nearly the same. The simulation and practical experimental results show that the proposed architecture can effectively improve the performance of the practical automatic target recognition system.

Bidirectional Potential Guided RRT* for Motion Planning

Requirement for high accuracy and speed of grasping operation for motion planning is very important. Motion planning algorithms for avoiding obstacles in narrow channels play a vital role for robotic arm effectively operating grasp tasks. The potential function-based RRT*-connect (P-RRT*-connect) algorithm for motion planning is presented by combining the bidirectional artificial potential field into the rapidly exploring random tree star (RRT*) in order to enhance the performance of the RRT*. The motion path is found out by exploring two path trees from the start node and destination node, respectively, with the rapidly exploring random tree star. Two trees advance each other at the same time according to the attractive potential field and the repulsion potential field generated by the artificial potential field method of sampled nodes until they meet. The P-RRT*-connect algorithm is especially suitable for solving the problem of narrow channels. The simulation results prove that the P-RRT*-connect algorithm is more efficient than potential Function-based RRT* (P-RRT*) regardless of the number of iterations or the running time. The experimental data show that the time for the P-RRT*-connect to find the optimal path from the starting node to the target node is half than that of the P-RRT*, and the number of iterations of the P-RRT*-connect is also about one-third less than that of the P-RRT* which is useful for real time.

Dynamic Modeling, Simulation, and Experimental Verification of a Wafer Handling SCARA Robot With Decoupling Servo Control

In this paper, we propose a novel coordinated control method based on decoupling servo control to design a 4-DOF direct-drive SCARA robot for wafer handling purpose. As the basis of decoupling servo control, the dynamic model of the SCARA robot is obtained with two methods, the Newton-Euler equation, and Lagrangian equation. The validity of this SCARA dynamic equation is confirmed by these two methods. Due to disturbance and model uncertainty, three PD plus robust controllers are individually applied to three axes of the SCARA robot, together with decoupling control on three physically dynamically highly coupled robotic arms. The inverse dynamics of the SCARA robot is analyzed by feedback linearization, and the experimental results show that above PD plus robust controllers and decoupling control reduce the position tracking error effectively. Performance meets with the high speed and high precision requirements in the wafer handling process. The experimental data shows that the decoupling control algorithm makes the SCARA robot performance improved a lot. The position errors during dynamic tracking movement and the static errors are reduced by 4 to 20 times.

Parallel processing of numerical simulation of two-phase flow in fractured reservoirs considering the effect of natural flow barriers using the streamline simulation method

Because of the large size of reservoirs and complexity of the fluid behavior, especially in fractured porous media, simulation of hydrocarbon reservoirs is costly to compute using common simulators based on an Eulerian grid. For this reason, the streamlines method, which offers high computational speed and low computational hardware requirements with suitable accuracy can replace common simulators. The current study investigated parallel processing of numerical simulation for two-phase flow in two-dimensional fractured porous media using the streamlines method in OpenMp programming model. For validation, the results of water flooding simulation were compared with the IMPES method and the effect of natural flow barriers for the injection wells has been modeled. The dual porosity model is used to model the fractured reservoirs and transport equations are solved independently on 1D streamlines. It was found that the ability and performance of the streamlines method is better for parallel processing than for other methods based on the Eulerian grid.

Optimization of critical speed of double spools with reverse rotation

Under the requirement of high speed, high pressure ratio and high thrust weight ratio, more and more aircraft engines adopt counter rotating technology. In this model, the F135 engine is used to research the dynamic characteristics of a dual rotor system with four supports supported by an intermediary. In this paper, the critical speed of the system is solved by the direct method. Compared with the Campell diagram, the eigenvalue problem of the required solution is greatly reduced. The critical speed is optimized by using genetic algorithm. Moreover, when the constraint of frequency forbidden zone is more severe, the elitist preserving genetic algorithm is used, which greatly reduces the required convergence algebra.

An underwater spoiler on a warship: why, when and how?

Abstract There are a lot of energy saving devices for ships on the market, but few have seen wide adoption on naval ships, with one exception: the bulbous bow. The bulbous bow was developed for naval ships in the early 20th century and is now widespread on a variety of ship designs. Many have wondered if the effect of the bulbous bow — reducing the resistance of a ship by reducing the bow wave — could be replicated somehow at the stern — by reducing the stern wave. This is exactly what is done by a novel and patented energy saving device called Hull Vane®. Invented by Dutch hydrodynamicist Dr Peter van Oossanen for an America’s Cup sailing yacht in the early 21st century, research over the years has shown that this wing-shaped appendage works best on ships that combine a relatively high displacement with a relatively high top speed requirement — even if most sailing hours are done at half speed. Examples are certain offshore vessels, superyachts, patrol vessels and naval ships. On offshore patrol vessels, the resistance reduction from the Hull Vane® ranges typically from 10 to 20% over the entire useful speed range. In this paper, the working principles of the Hull Vane® will be described to give a better under-standing of the device. An overview will be given of the work carried out on naval ships and coastguard ships (25 to 142 m), based on Computational Fluid Dynamics studies, model tests and full-scale applications. The question ‘Why?’ will be answered by translating the hydrodynamic effects to concrete capability improvements for naval ships: a lower fuel consumption, a longer range, reduced signature, a higher top speed and improved seakeeping. The question ‘When?’ will zoom in on whether a Hull Vane® is something to be included in a newbuild or if it is something to be retrofitted to an existing ship. Finally the answer to the question ‘How?’ will explain the process of either integrating a Hull Vane® in a newbuild project or retrofitting it during a midlife upgrade of an existing ship.

Development of a high flow rate piston pump for rocket engines

There is a need for cheaper small satellite rocket launchers. One way of reducing costs is to reduce the cost of individual components. We describe here the development of an inexpensive piston pump for rocket engine applications. It demonstrates that it can deal with the combined requirements of high flow rate and operating speed at cryogenic temperatures without incurring the costs normally associated with such performance.

Ceramic motorized spindle for NC machine tool

In order to reduce the inertia force and centrifugal force generated when the spindle bearing unit rotates at a high speed and to increase its limit rotation speed, precision, rigidity, service life and reliability, it can meet the high speed and high precision requirements of the spindle system. The innovative design of the ceramic motorized spindle unit, testing and analysis of the comprehensive performance of ceramic motorized spindle and the related research on the intelligentization of the ceramic motorized spindle were carried out. Finally, the current limitations and challenges are discussed, and the future development trend of the numerically-controlled machine tool ceramic motorized spindle is forecasted.

Effect of Tempering Temperatures on Tensile Properties and Rotary Bending Fatigue Behaviors of 17Cr2Ni2MoVNb Steel

With the rapid development of the automotive industry in China, the common gear steels no longer meet the high speed and heavy load requirements of the automotive industry. 17Cr2Ni2MoVNb steel is a new type of gear steel in the automotive industry, but the mechanical properties of 17Cr2Ni2MoVNb are not well documented. In this study, the tensile properties and rotary bending fatigue behaviors of 17Cr2Ni2MoVNb were investigated, (quenched at 860 °C and tempered at 180, 400, 620 °C); the microstructures and fracture surface were analyzed using an optical microscope, scanning electron microscopy and transmission electron microscopy. The results show that at higher tempering temperatures, the tissue was denser, and the residual austenite transformed into lower bainite or tempered martensite. Dislocation density reduced while tempering temperature increased. Moreover, the samples with a tempering temperature of 180 °C exhibited the highest tensile strength of 1456 MPa, in addition to fatigue limits of 730, 700 and 600 MPa at temperatures of 180, 400, and 620 °C, respectively.

Numerical simulation of the shock wave in the closed resonator using 1D Lagrange’s approach

The comparison of the results of calculating the shock wave in a two-dimensional acoustic resonator based on the 1D Lagrange approach with experimental, analytical and numerical results of other authors obtained on the basis of 2D simulation is presented. The shock wave, which arises at frequencies close to the first resonant one, is investigated. It’s shown that the 1D Lagrange approach gives a satisfactory agreement with the results of 2D simulations of other authors as well as with results obtained using CFD-package Fluent in this work. It’s shown that Lagrange’s approach due to exact formulation of the boundary condition, high calculation speed and minimum memory requirements can be effectively used to solve a number of two-dimensional problems, as well as to verify the reliability of other numerical methods.

Molecular switch-modulated fluorescent copper nanoclusters for selective and sensitive detection of histidine and cysteine.

A novel assay for histidine and cysteine has been constructed based on modulation of fluorescent copper nanoclusters (CuNCs) by molecular switches. In our previous work, a dumbbell DNA template with a poly-T (thymine) loop has been developed as an excellent template for the formation of strongly fluorescent CuNCs. Herein, for the first time, we established this biosensor for sensing two amino acids by using dumbbell DNA-templated CuNCs as the single probe. Among 20 natural amino acids, only histidine and cysteine can selectively quench fluorescence emission of CuNCs, because of the specific interaction of these compounds with copper ions. Furthermore, by using nickel ions (Ni2+) and N-ethylmaleimide as the masking agents for histidine and cysteine respectively, an integrated logic gate system was designed by coupling with the fluorescent CuNCs and demonstrated selective and sensitive detection of cysteine and histidine. Under optimal conditions, cysteine can be detected in the concentration ranges of 0.01-10.0μM with the detection limit (DL) of as low as 98pM, while histidine can be detected in the ranges of 0.05-40.0μM with DL of 1.6nM. In addition, histidine and cysteine can be observed with the naked eye under a hand-held UV lamp (DL, 50nM), which can be easily adapted to automated high-throughput screening. Finally, the strategy has been successfully utilized for biological fluids. The proposed system can be conducted in homogeneous solution, eliminating the need for organic cosolvents, separation processes of nanomaterials, or any chemical modifications. Overall, the assay provides an alternative method for simultaneous detection of cysteine and histidine by taking the advantages of high speed, no label and enzyme requirement, and good sensitivity and specificity, and will satisfy the great demand for determination of amino acids in fields such as food processing, biochemistry, pharmaceuticals, and clinical analysis. Graphical abstract.

Development of single row automatic transplanting device for potted vegetable seedlings

In China, low degree of automation seriously affects the working efficiency and quality in vegetable transplanting. As one of the most important vegetables in China even in the world, tomato was taken as the research object in this study. An automatic single-row transplanting device was designed, based on the statistical analysis of the physical and mechanical properties of tomato seedlings of a typical variety. Based on the technology of mechatronics, the device integrated the functions of transporting seedling tray, automatic seedling extraction and mechanical planting. The kinematics orthogonality solution combined with the dynamic sequence solution method was used to optimize and analyze the kinematic parameters of the automatic seeding mechanism, and the “sickle” trajectory was obtained. According to the position and movement requirement for taking and dropping seedling, the mechanical conditions and the working parameters of key execution parts were obtained by using analytic drawing method to analyze the mechanical condition of seedling collecting mechanism. The transplanting experiment was conducted at room temperature of 25°C, and the age and moisture content of the seedlings were 40 d and 55%, respectively. The results showed that the highest success rate was 92.59%, and the lowest rate of leakage was 23.13%, when the transplanting frequency was 60 plants/min. The lowest success rate was 77.78%, and the highest rate of leakage was 38.75%, when transplanting frequency was 120 plants/min. When the transplanting frequency is between 60-90 plants/min, the device can meet the requirement of high speed transplanting for potted vegetable seedling. Keywords: potted vegetable seedling, seedling mechanism, automatic transplanting, tomato seedling, transplanting experiment DOI: 10.25165/j.ijabe.20181103.3969 Citation: Jin X, Li D Y, Ma H, Ji J T, Zhao K X, Pang J. Development of single row automatic transplanting device for potted vegetable seedlings. Int J Agric & Biol Eng, 2018; 11(3): 67–75.

Transient- and probabilistic neural network-based fault classification in EHV three-terminal lines

This paper presents a fast and accurate fault classifier for three-terminal transmission circuits. Traditional phasor-based methods fail to meet the high speed requirements of modern power grids and necessitate alternative solutions. The transient-based schemes use advanced signal processing techniques to achieve fast and accurate fault classification. As the three-terminal lines experience very pronounced transients during faults, the proposed method makes use of the fault-generated transients to quickly and correctly classify the fault. Many transient-based schemes fail to give the required accuracy since the transient patterns with relay-measured signals are highly influenced by fault conditions. Therefore, a thorough analysis of transient patterns is carried out in this paper, and based on the typical patterns revealed by the analysis of fault-generated transients an effective classification algorithm is developed. For high-speed classification, only a quarter-cycle of postfault voltage signals measured at the relay points will be processed for feature extraction using wavelet transform. The algorithm includes a hybrid procedure based on a probabilistic neural network for tackling the effects of fault inception angle and fault resistance in transient variations. Particularly, it is designed to overcome the problem with double-line-to-ground fault classification. The technique is simple and extensive simulation studies and comparison substantiate the efficacy of the proposed method under different fault conditions.

RETRACTED ARTICLE: Research on fine grained software radio communication algorithm based on GPU parallel processing technology

With the development of information technology and the progress of science and technology, broadband wireless communication is changing people’s way of life. Traditional software radio communication algorithms can’t meet high speed and efficient data processing requirements, and GPU parallel processing technology arises at the historic moment. Based on this, starting with GPU and CPU, the relationship between parallel and serial operation was studied. According to the characteristics of GPU with high performance, high bandwidth, high parallelism and programmable architecture, the principle of parallel Turbo algorithm in GPU is discussed. The turbo decoding algorithm is studied from both MAP and SOVA, and the total structure of the GPU decoder based on GPU and the subroutine thread distribution are proposed. And the result shows that GPU parallel processing technology based on the fine grained software radio communication algorithm, not only increases the granularity of fine-grained parallel particles, but also improves the operation speed.

A Simulation Study of Active Disturbance Rejection Control for Gravure Register System

According to two-color printing register system working principle, a mathematical model of two-color register error in shaftless driving mode is established, and extended to four-color register error model further more. Aiming to this model, an active disturbance rejection control (ADRC) controller and control system for gravure register are designed, then the simulation system is build also. The simulation results show that the designed register control system is able to realize a high precision control for the multi-color register system, this provides a viable option for gravure printing register system which meets to the requirements of high precision, high speed and low reject rate.

Development of single row automatic transplanting device for potted vegetable seedlings

In China, low degree of automation seriously affects the working efficiency and quality in vegetable transplanting. As one of the most important vegetables in China even in the world, tomato was taken as the research object in this study. An automatic single-row transplanting device was designed, based on the statistical analysis of the physical and mechanical properties of tomato seedlings of a typical variety. Based on the technology of mechatronics, the device integrated the functions of transporting seedling tray, automatic seedling extraction and mechanical planting. The kinematics orthogonality solution combined with the dynamic sequence solution method was used to optimize and analyze the kinematic parameters of the automatic seeding mechanism, and the “sickle” trajectory was obtained. According to the position and movement requirement for taking and dropping seedling, the mechanical conditions and the working parameters of key execution parts were obtained by using analytic drawing method to analyze the mechanical condition of seedling collecting mechanism. The transplanting experiment was conducted at room temperature of 25°C, and the age and moisture content of the seedlings were 40 d and 55%, respectively. The results showed that the highest success rate was 92.59%, and the lowest rate of leakage was 23.13%, when the transplanting frequency was 60 plants/min. The lowest success rate was 77.78%, and the highest rate of leakage was 38.75%, when transplanting frequency was 120 plants/min. When the transplanting frequency is between 60-90 plants/min, the device can meet the requirement of high speed transplanting for potted vegetable seedling. Keywords: potted vegetable seedling, seedling mechanism, automatic transplanting, tomato seedling, transplanting experiment DOI: 10.25165/j.ijabe.20181103.3969 Citation: Jin X, Li D Y, Ma H, Ji J T, Zhao K X, Pang J. Development of single row automatic transplanting device for potted vegetable seedlings. Int J Agric & Biol Eng, 2018; 11(3): 67–75.

Deep learning for wireless physical layer: Opportunities and challenges

Machine learning (ML) has been widely applied to the upper layers of wireless communication systems for various purposes, such as deployment of cognitive radio and communication network. However, its application to the physical layer is hampered by sophisticated channel environments and limited learning ability of conventional ML algorithms. Deep learning (DL) has been recently applied for many fields, such as computer vision and natural language processing, given its expressive capacity and convenient optimization capability. The potential application of DL to the physical layer has also been increasingly recognized because of the new features for future communications, such as complex scenarios with unknown channel models, high speed and accurate processing requirements; these features challenge conventional communication theories. This paper presents a comprehensive overview of the emerging studies on DL-based physical layer processing, including leveraging DL to redesign a module of the conventional communication system (for modulation recognition, channel decoding, and detection) and replace the communication system with a radically new architecture based on an autoencoder. These DL-based methods show promising performance improvements but have certain limitations, such as lack of solid analytical tools and use of architectures that are specifically designed for communication and implementation research, thereby motivating future research in this field.

High speed tracking control of ball screw drives

This paper presents a new method to achieve the requirement of high speed and high precision for ball screw drive. First, a PI controller is adopted to increase the equivalent structural damping in the velocity loop. Next, the design of the position controller is implemented by a two-stage method. The Doubly Coprime Factorization Disturbance Observer (DCFDOB) is developed to suppress disturbance and resist modelling error in the inner loop, while the outer loop is then designed based on method to extend the system bandwidth over first resonant frequency so that high speed and high accuracy can be achieved. Finally, a feedforward controller is implemented to improve tracking performance. The experiment results showed that the proposed method has smaller tracking error and better performance for suppressing disturbance when compared to the conventional cascaded P-PI control.

Development of transition edge sensors with rf-SQUID based multiplexing system for the HOLMES experiment

Measuring the neutrino mass is one the most compelling issue in particle physics. HOLMES is an experiment funded by the European Research Council for a direct measurement of neutrino mass. HOLMES will perform a precise measurement of the end point of the Electron Capture decay spectrum of 163Ho in order to extract information on neutrino mass with a sensitivity as low as 1 eV. HOLMES, in its final configuration will deploy a 1000 pixel array of low temperature microcalorimeters: each calorimeter consists of an absorber, where the Ho atoms will be implanted, coupled to a Transition Edge Sensor thermometer. The detectors will be kept at the working temperature of ∼70 mK using a dilution refrigerator. In order to gather the required 3 × 1013 events in a three year long data taking with a pile up fraction as low as 10−4, detectors must fulfill rather high speed and resolution requirements, i.e. 10 µs rise time and 4 eV resolution. To ensure such performances with an efficient read out technique for very large detectors array kept at low temperature inside a cryostat is no trivial matter: at the moment, the most appealing read out technique applicable to large arrays of Transition Edge Sensors is rf-SQUID multiplexing. It is based on the use of rf-SQUIDs as input devices with flux ramp modulation for linearisation purposes; the rf-SQUID is then coupled to a super-conductive λ/4-wave resonator in the GHz range, and the modulated signal is finally read out using the homodyne technique.

Adaptive Fractional Order PI Controller Design for a Flexible Swing arm System Via Enhanced Virtual Reference Feedback Tuning

AbstractFlexible swing arm system (FSAS) is one of the most important components in the LED packaging industry. The trajectory tracking performance of the FSAS will directly affect the efficiency and accuracy of the LED packaging equipment. In order to meet the high precision and high speed requirements, this paper proposes an adaptive fractional order proportional integral (AFOPI) control method based on enhanced virtual reference feedback tuning (EVRFT). In this method, the AFOPI controller is applied to handle the fractional order characteristics of the FSAS. EVRFT is used to tune the AFOPI controller in a real‐time way to accommodate the time‐varying operating conditions. The proposed method is facilitated with two advantages: 1) only input/output measured data are fully utilized during the recursive tuning process without using model information of the controlled FSAS; 2) an improved adaptive law is incorporated in EVRFT to reduce the computation burden and provide an unbiased estimate for the ideal controller simultaneously. Thus, the conventional VRFT is enhanced both in efficiency and accuracy. The stability of the proposed method is guaranteed by rigorous theoretical analysis. Finally, experimental results are presented to verify the effectiveness of the EVRFT‐based AFOPI controller.