Simulation Test Method Research Articles

Research on Integrated Decision Control Algorithm for Autonomous Vehicles Under Multi-Task Hybrid Constraints in Intelligent Transportation Scenarios

In order to improve the decision-making and control effect of autonomous vehicles, in this paper, combined with literature research and process analysis, the control algorithm of autopilot vehicle is analyzed, and the driving process is analyzed combined with the flow method. In order to improve the effect of autonomous driving, with the support of improved algorithms, an integrated decision-making control system for autonomous vehicles under multi-task constraints in intelligent traffic scenarios is constructed, and system performance is improved by simulating autonomous driving decisions in a variety of complex situations. Moreover, this paper designs the road driving model according to actual needs, sets the functional modules of the entire system, and build the overall framework of the system. Finally, in order to study the integrated decision-making effect of this system, this paper conducts test research by designing a simulation test method. From the simulation test results, it can be seen that the intelligent decision-making system for autonomous vehicles constructed in this paper has certain effects.

Overview of Spindle-Coupled Road Simulation Test Method for Vehicle Structure Durability

The durability of vehicle structure is one of the important performances to evaluate the quality of automobiles, and it has been paid more and more attention by automobile manufacturers and consumers. In the whole vehicle development process, automotive structural durability testing is essential. With the advantages of high test accuracy and short test cycle, road simulation test has become an effective test method in the vehicle development stage. Among them, the spindle-coupled road simulation test can most comprehensively reproduce the excitation of the road to the vehicle. The relevant test technology is synchronized with the rapid development of automotive products and keeps pace with the times, becoming one of the most deeply cultivated test technologies in the industry.

Research on performance test analysis method of mechanical structure based on measured error / virtual simulation

Mechanical errors seriously affect the transmission performance of mechanical structure, especially for high-precision mechanical structure. With the development of virtual simulation technology, the performance test of mechanical structure in virtual environment is gradually applied. Under the background, this paper takes the movable tooth reducer as the research object and puts forward a virtual performance test method by combing test errors with virtual simulation technology. The tooth profile errors of key components of the reducer are obtained by optical scanning, and the simulation test is carried out. Meanwhile, the accuracy of the simulation test is verified by the implementation of vibration test. The results show that both the simulated vibration acceleration and the experimental test vibration acceleration show a double-peak variation trend, and the frequency difference between the two peaks is less than 5%. Therefore, the simulation test method proposed in this paper can effectively evaluate the performance of mechanical structures.

АНАЛІЗ ВПЛИВУ МАРШРУТНИХ ТА ЕКСПЛУАТАЦІЙНИХ ФАКТОРІВ НА ТРАНСПОРТНУ ЕНЕРГОЕФЕКТИВНІСТЬ МІСЬКИХ ПАСАЖИРСЬКИХ ПЕРЕВЕЗЕНЬ

The article establishes the relevance of using simulation test methods of technical and technological energy saving and increasing technological competitiveness of motor transport services according to energy criteria when renewing the fleet of buses for urban passenger transportation. It is shown that the existing methodology of bus transport organization does not provide urban passenger bus fleet renewal according to the concept of operational and technological energy saving and improvement of technological competitiveness of automobile transport services. According to the results of multivariate modeling the interrelation between the tasks of formation of energy saving technologies of passenger urban road transport and improvement of the method of technological selection of buses for urban routes with taking into account different (technical, operational and routing) factors. Quantitative dependences of influence of technical, operational and route factors on indexes of transport energy efficiency of transportations and operational intensity of machine procedures of bus transport technologies are received. The object of the research is the energy-consuming process of urban bus transportations taking into account the influence of various factors (technical, operational and route factors). Purpose of work – analysis of route and operational factors influence on transport energy efficiency of urban passenger transportation based on test modeling of bus operation as resource-technical means of motor transport technology. The method of the research is evolution-simulation analysis of transport energy efficiency of transportation and operational intensity of machine procedures of bus transportation technology in multiphase test operations, in which city route network conditions and different factors of bus transportation are taken into account, using software and methods of test-simulation analysis of generalized type vehicles of the NTU Department of Transport Technologies. 407 The results of the article and the method can be implemented by managers of passenger motor transport for long-term management of conceptually oriented development of resource and technological basis of motor transport enterprises and technological processes of bus transportation in cities. KEYWORDS: BUS, URBAN PASSENGER TRANSPORTATION, TRANSPORT ENERGY EFFICIENCY, OPERATIONAL INTENSITY OF MACHINE PROCEDURES, TECHNOLOGY TECHNICAL AND OPERATIONAL FACTORS, EVOLUTIONARY MODELING

Mechanism, theory and application research of a rotating electromagnetic energy harvester suitable for multi-directional excitation

Energy harvesting in multi-directional excitation for human wearable devices is a challenge. A rotating electromagnetic energy harvester (REMEH) based on an eccentric rotor structure is proposed in this paper. Two poles of the magnets in the REMEH are alternately arranged in a ring. The electrical output characteristics of the energy harvester are analyzed through theoretical, numerical simulation and experimental testing methods based on the establishment of magnetic flux density models, the coil induced voltage, and the excitation direction of the eccentric rotor structure. Theoretical analysis and experimental results show that the design of the eccentric rotor structure is well adapted to multi-directional and irregular excitation. The circular staggered arrangement of the magnets effectively increases the output voltage and output power. The results show that the average output power increases slowly when the walking speed increases from 1 to 3 km h−1, and the average output power increases substantially when the walking speed increases from 3 to 5 km h−1. When the walking speed is 1 and 3 km h−1, the average output power is 0.439 and 0.638 mW, respectively. At a walking speed of 5 km h−1, the average output power increases rapidly to 1.68 mW, corresponding to a power density of 16.59 μW g−1. This high-performance energy harvester can provide effective power supply for wearable devices or low-powered sensors.

Rearward-Facing Infant Child Restraint Systems with Support Legs in Frontal and Frontal-Oblique Impacts.

Previous studies of support legs in rearward-facing infant CRS models have focused on frontal impacts and have found that the presence of a support leg is associated with a reduction in head injury metrics. However, real-world crashes often involve an oblique principal direction of force. The current study used sled tests to evaluate the effectiveness of support legs in rearward-facing infant CRS models for frontal and frontal-oblique impacts with and without a simulated front row seatback. Frontal and frontal-oblique impact sled tests were conducted using the simulated Consumer Reports test method with and without the blocker plate, which was developed to represent a front row seatback. The Q1.5 anthropomorphic test device (ATD) was seated in rearward-facing infant CRS models, which were tested with and without support legs. The presence of a support leg was associated with significant reductions of head injury metrics below injury tolerance limits for all tests, which supports the findings of previous studies. The presence of a support leg was also associated with significant reductions of peak neck tensile force. The presence of the blocker plate resulted in greater head injury metrics compared to tests without the blocker plate, but the result was non-significant. However, the fidelity of the interaction between the CRS and blocker plate as an adequate representation of the interaction that would occur in a real vehicle is not well understood. The findings from the current study continue to support the benefit of support legs in managing the energy of impact for a child in a rearward-facing CRS.

Numerical and Experimental Research on Single-Valve and Multi-Valve Resonant Systems

Multiple valves in the pipeline system belong to obvious periodic structure distribution types. When a high-speed airstream flows through the pipeline valve, it produces obvious aero-acoustic and acoustic resonance. Acoustic resonant systems with single and six-pipe valves were investigated to understand the flow and acoustic characteristics using a numerical simulation method and testing method. The strongest acoustic resonance occurred at a specific flow velocity with a corresponding Strouhal number of 0.47 corresponding to the geometric parameters in the paper. Moreover, acoustic resonance occurred in a certain velocity range, rather than increasing with the increase of the velocity of the pipeline. This regular increase provided an important theoretical basis for the prediction of the acoustic resonant and ultimate acoustic load of a single-valve system. When the pipeline was attached with multiple valves and the physical dimension was large, the conventional aero-acoustics calculation results were seriously attenuated at high frequency; the calculation method involving a cut-off frequency in this paper was presented and could be used to explain the excellent agreement of the sound pressure level (SPL) below the cut-off frequency and the poor agreement above the cut-off frequency. A new method involving steady flow and stochastic noise generation and radiation (SNGR) was proposed to obtain better results for the SPL at the middle and high frequencies. The comparison results indicated that the traditional method of Lighthill analogy and unsteady flow could accurately acquire aerodynamic noise below the cut-off frequency, while the new method involving steady flow and SNGR could quickly acquire aerodynamic noise above the cut-off frequency.

Evaluating the adsorption performance of Tenax TA® in different containers: An isolation tool to study the bioaccessibility of nitro-PAHs in spiked soil

The improved in vitro gastrointestinal simulation methods, with the addition of the adsorption sink, are considered as a promising tool for predicting the bioaccessibility of contaminants. However, the problem associated with the recovery of the adsorption sink from the complex matrix needs more understand. Although previous studies tried to solve this shortcoming by using the containers (a vessel to hold the adsorption sink), there is no systematic comparison study on the impact of containers on bioaccessibility till now, especially for nitro-polycyclic aromatic hydrocarbons (nitro-PAHs). In order to understand the problem, commonly used containers in previous studies (dialysis bags and stainless-steel screen) were selected and deployed in the Fed Organic Estimation Human Simulation Test (FOREhST) method to compare the effects of these containers on the bioaccessibility of nitro-PAHs desorbed from the five different types of soils into the gastrointestinal fluid (GIF). Results showed that in order to maintain a constant sorptive gradient for the high molecular weight (MW) nitro-PAHs, 0.25 g of Tenax TA® were required in FOREhST. Compared with Tenax TA® encapsulated in dialysis bag (Tenax-EDBG), the use of Tenax TA® encapsulated in dissolution basket (Tenax-EDBT) significantly increased the bioaccessibility of nitro-PAHs in the soil from 5.6–31.4% to 17.2–70.6%, due to the better diffusion performance. The bioaccessibility of nitro-PAHs by FOREhST extraction with Tenax-EDBT showed a significant negative correlation with soil total organic carbon (TOC), whereas a weak correlation with pH. This study provides the researchers with a more standardized in vitro method to quantify the bioaccessibility of PAHs and their derivatives in soil.

Experimental investigation of pulse‐type ground motion effects on a steel building with nonlinear viscous dampers

AbstractNear‐fault pulse‐type ground motions have characteristics that are substantially different from ordinary far‐field ground motions. It is essential to understand the unique effects of pulse‐type ground motions on structures and include the effects in seismic design. This paper investigates the effects of near‐fault pulse‐type ground motions on the structural response of a 3‐story steel structure with nonlinear viscous dampers using the real‐time hybrid simulation (RTHS) testing method. The structure is designed for 75% of the code‐specified design base shear strength. In the RTHS, the loop of action and reaction between the experimental and numerical partitions are executed in real time, accurately capturing the velocity pulse effects of pulse‐type ground motions. A set of 10 unscaled pulse‐type ground motions at the design basis earthquake (DBE) level is used for the RTHS. The test results validated that RTHS is a viable method for experimentally investigating the complicated structural behavior of structures with rate‐dependent damping devices, and showed that the dampers are essentially effective in earthquake hazard mitigation effects involving pulse‐type ground motions. The average peak story drift ratio under the set of pulse‐type ground motions is 1.08% radians with a COV value less than 0.3, which indicated that structural system would achieve the ASCE 7–10 seismic performance objective for Occupancy Category III structures under the DBE level pulse‐type ground motions. Additionally, a nonlinear Maxwell model for the nonlinear viscous dampers is validated for future structural reliability numerical studies involving pulse‐type ground motions.

Research on Overload Signal of New Impact Body Based on Air Cannon Test and Simulation

Air cannon simulation test method is a common method to generate high overload signal. In this paper, a new impact body model for air gun test is proposed. Based on the model, the impact dynamic theory is analysed, and the variation law of high overload signal in accelerometer due to multiple reflection and transmission of stress wave in the impact process is studied. The finite element model is established by using ANSYS / LS-DYNA software to simulate and analyse the impact process, and a test platform is built to verify the simulation. The test results and simulation results show that the impact body can generate a “W” shape high overload signal during the impact process, which also verifies the rationality of the theoretical analysis. The methods and conclusions of this paper have certain significance for the study of the new type of impact body and the high overload signal produced by the impact test.

Analysis of solar interference simulation test for flame detectors

The light interference is an important reason for the false alarm or blindness of the flame detectors, and the effect of sunlight interference is particularly significant. In order to meet the requirements for the evaluation of the anti-sunlight interference performance of the flame detector, it is necessary to classify the solar interference severity according to the light climate data. On this basis, the solar interference simulation equipment and test method with quantitative test are designed. Through tests under different seasons, times and light conditions, the reliability and effectiveness of the test equipment and test methods are verified, the measurement uncertainty is calculated. Test results provide technical support for the standardization of sunlight interference test.

A New Dynamic Simulation Test Method of Intelligent Electricity Metering System

Electricity metering is the core supporting technology for realizing accurate perception of electricity consumption, reasonable dispatching of power grids, rapid market response, diversified charging and new forms of electricity marketing. However, due to the significant differences in the actual metering environment, the operation of the electricity metering and information collection system is unstable, showing many problems such as unsuccessful parameter delivery and low acquisition success rate, which severely restricts the development of smart grid two-way interactive technology and the realization of smart electricity consumption in the last mile. There is an urgent need for a reliable and accurate dynamic simulation and systematic testing method to realize the reproduction and testing of various field faults. In this paper, we propose a new type of dynamic simulation test method for intelligent electricity metering system, which can realize the performance test, fault dynamic simulation, location and recovery of each functional unit of the master station, collection terminal and smart meter. Through experimental testing, our dynamic simulation test methods can realize the rapid recurrence of on-site problems, improve the high reliability and normal operation of the electric energy metering information collection system.

Digital-analog hybrid dynamic simulation test method and platform for hybrid DC circuit breakers

Digital-analog hybrid dynamic simulation test method and platform for hybrid DC circuit breakers

Research on the Regular of Underground Pressure by Similarity Simulation

Correct and reasonable estimation of roof pressure regular and mine pressure behavior is conducive to better service of mine safety mining. Based on 1304 working face of Heba coal mine as the engineering research background, the regular of underground pressure, roof movement and roof caving are studied by using similar material simulation test and field observation methods. Through the simulation test of similar materials and field observation, it is concluded that: The first pressure interval of the working face is about 50–60 m, and the periodic pressure interval is about 15-20 m. The distribution range of advance abutment pressure is about 50 m away from the working face, the peak stress appears in the range of 6–15 m in front of coal wall, and the stress concentration coefficient is between 1.25 and 1.4. It shows that the results of similar simulation experiment and field observation are basically consistent, which can guide engineering practice.

Hybrid simulation tests of high-strength steel composite K-eccentrically braced frames with spatial substructure

Based on the spatial substructure hybrid simulation test (SHST) method, the seismic performance of a high-strength steel composite K-eccentrically braced frame (K-HSS-EBF) structure system is studied. First, on the basis of the existing pseudostatic experiments, a numerical model corresponding to the experimental model was established using OpenSees, which mainly simulated the shear effect of the shear links. A three-story and five-span spatial K-HSS-EBF was taken as the prototype, and SHST was performed with a half-scale SHST model. According to the test results, the validity of the SHST model was verified, and the main seismic performance indexes of the experimental substructure under different seismic waves were studied. The results show that the hybrid simulation results are basically consistent with the numerical simulation results of the global structure. The deformation of each story is mainly concentrated in the web of the shear link owing to shear deformation. The maximum interstory drifts of the model structure during Strength Level Earthquake (SLE) and Maximum Considered Earthquake (MCE) meet the demands of interstory limitations in the Chinese seismic design code of buildings. In conclusion, the seismic response characteristics of the K-HSS-EBFs are successfully simulated using the spatial SHST, which shows that the K-HSS-EBFs have good seismic performance.

Identification of Typical Behaviors of Market Subjects in Competitive Power Market Environment

In the power market, some illegal behaviors of market subjects violate the market rules. There also are some potential harmful behaviors, such as profiteering pricing, speculation, alliance, which do not violate market rules directly. These harmful market behaviors impair the competitiveness and effectiveness of the market, cause adverse effect for the optimal allocation of limited resources. Consequently, it will impair the efficiency of the electricity market. Market illegal behaviors can be judged, punished and controlled according to market rules; However, harmful market behaviors are difficult to be identified and controlled according to market rules, so an effective method must be established to identify, monitor and control them. According to the different characteristics of potentially hazardous behaviors, four methods are proposed in this paper, namely, index supervision method, quotation behavior supervision method, trading behavior analysis method based on expert system and market simulation test method to identify the illegal behaviors in the power market. Then, this paper takes the compliance analysis of market player behavior and the compliance analysis of electricity purchase price as an example to carry out simulation test.

Influence of temperature on the interaction of metal veins and hydraulic fractures in shale formations: Experiment and simulation

In the field construction of shale oil (gas) hydraulic fracturing, the veins present in the shale may deflect the propagation path of hydraulic fractures. The metal chalcopyrite veins are widely contained in Jimusar Shale, but the effect of the metal veins on the fracture propagation at different temperatures is still unclear. Based on the extended finite element simulation and semicircular bending test method, the effect of temperature on the interaction law of the metal veins and hydraulic fractures is studied. The results show that the fracture propagation path in the rock sample is more tortuous with the increasing temperature; Compared with the 23 °C rock sample, the fracture toughness of rock samples without the vein and with the vein at 200 °C increase by 7.79% and 22.78%, respectively. The higher the temperature, the more difficult it is for the fracture to offset at the interface between the rock and the metal veins. But the temperature does not affect the distance of fractures offset. The results of this study can provide a reference for the design of hydraulic fractures of shale with the metal veins.

Solving the Logistics Problems of Production Investments with a Simulation Test Method

As a result of the increasingly diversified customer needs, investments to transform the production system are gaining prominence. Due to the complexity of the transformation, in many cases there are logistical problems that hinder the current and/or future satisfaction of customer needs due to inadequate planning. The paper also explores the types of possible logistics problems that may occur after the implementation of the investments, as well as the steps of applying a simulation test method to address them.

Model comparison and management optimization of pump production organization

This manuscript aims to explore the impact of production organization mode on the inventory and delivery rate of pump enterprises and optimize the production management of pump enterprises. The system dynamic model and simulation test method were used to compare the changes in the inventory, productivity and delivery rate of pump enterprise under the traditional make-to-order (MTO) and make-to-stock (MTS) organizational modes. Following the above analysis, the optimized pump order production management mode combined with MTO & MTS was put forward, and the fuzzy comprehensive evaluation method was used to evaluate the three above modes. When customer demand scarcely fluctuates and is easily predictable, the MTO production organization mode can be adopted; when customer demand fluctuates sharply and is difficultly predicted, the MTO & MTS combined mode should be selected. According to the results of the fuzzy comprehensive evaluation, the MTO & MTS mode is the best choice for pump enterprises. Considering that the pump demand is sensitive to the season and natural environment, the optimized mode is suitable for the production and inventory management of pump enterprise.

Evaluation of the geometallurgical indices for comminution properties at Sarcheshmeh porphyry copper mine, Iran

Geometallurgy has become an important tool to predict the processing behaviour of ores, and to decrease the production risks associated with the variable nature of economic mineral deposits. Understanding the ore variability and subsequently the response of the ore to processing are considered to be the most important functions of an accurate geometallurgical study. In this paper geometallurgical indices for grinding properties of a copper ore are investigated. Geometallurgical index (GI) is described as any geological feature which makes a footprint on the processing performance of the ores. A comprehensive study at Sarcheshmeh porphyry copper mine was undertaken. This included the process responses of the ore such as grade, recovery and plant throughput as possible geometallurgical indices. In this paper the effects of rock breakage variability on the plant throughput and energy consumption are presented. Ninety samples were collected based on geological features including lithology, hydrothermal alteration, and geological structures. The samples were characterized using X-ray diffraction, X-ray fluorescence, electron and optical microscopy. A small scale simulated test method for Bond ball mill work index (BWI) was used to perform the comminution examinations. The results showed that BWI values vary from 5.67 kWh/t to 20.21 kWh/t. Examination of the possible correlations between BWI and the geological features showed that the key geological feature related to comminution variability is lithology. In addition, the hydrothermal alteration would be an effective parameter in the period that the plant is fed with a single lithology.