Virtual Test Platform Research Articles

Energy Management Systems’ Modeling and Optimization in Hybrid Electric Vehicles

Optimization studies for the energy management systems of hybrid electric powertrains have critical importance as an effective measure for vehicle manufacturers to reduce greenhouse gas emissions and fuel consumption due to increasingly stringent emission regulations in the automotive industry, strict fuel economy legislation, continuously rising oil prices, and increasing consumer awareness of global warming and environmental pollution. In this study, firstly, the mathematical model of the powertrain and the rule-based energy management system of the vehicle with a power-split hybrid electric vehicle configuration are developed in the Matlab/Simulink environment and verified with real test data from the vehicle dynamometer for the UDDS drive cycle. In this way, a realistic virtual test platform has been developed where the simulation results of the energy management systems based on discrete dynamic programming and Pontryagin’s minimum principle optimization can be used to train the artificial neural network-based energy management algorithms for hybrid electric vehicles. The average fuel consumption in relation to the break specific fuel consumption of the internal combustion engine and the total electrical energy consumption of the battery in relation to the operating efficiency of the electrical machines, obtained by comparing the simulation results at the initial battery charging conditions of the vehicle using different driving cycles, will be analyzed and the advantages of the different energy management techniques used will be evaluated.

High-Speed Virtual Flight Testing Platform for Performance Evaluation of Pitch Maneuvers

To research serious nonlinear coupling problems among aerodynamics, flight mechanics, and flight control during high maneuvers, a virtual flight testing platform has been developed for a large-scale, high-speed wind tunnel, based on the real physical environment, and it can significantly mitigate risks and reduce the costs of subsequent flight tests. The platform of virtual flight testing is composed of three-degrees-of-freedom model support, measuring devices for aerodynamic and motion parameters, a virtual flight control system, and a test model. It provides the ability to realistically simulate real maneuvers, investigate the coupling characteristics of unsteady aerodynamics and nonlinear flight dynamics, evaluate flight performance, and verify the flight control law. The typical test results of a pitch maneuver with open-loop and closed-loop control are presented, including a one-degree-of-freedom pitch motion and a two-degrees-of-freedom pitch and roll motion. The serious pitch and roll-coupled motion during a pitch maneuver at a high angle of attack is revealed, and the flight control law for decoupled control is successfully verified. The comparison of the test results and the flight data of a real pitch maneuver proves the reliability and capability of virtual flight testing.

Double-layer control architecture for motion and torque optimisation of autonomous electric vehicles

Optimising energy autonomy for autonomous electric vehicles is a significant challenge in sustainable and environmentally friendly mobility. To this end, we propose a novel double-layer control architecture designed to drive the longitudinal motion of electric vehicles equipped with a regenerative braking system. The first layer resembles an Adaptive Cruise Control, while the second one is enabled during the braking phase and is devoted to the blending between the motor torque and the hydraulic one. This layer is synthesised as a Nonlinear Model Predictive Control strategy so as to maximise the efficiency of the regenerative system. The control architecture, by combining the two control strategies, allows to reduce the overall energy consumption for electric vehicles, while simultaneously ensuring a safer, more sustainable, and comfortable driving experience. Additionally, this combination is capable of compensating for any efficiency issues arising from external factors, such as different traffic conditions encountered by the vehicle. To evaluate the effectiveness of the proposed control architecture, extensive simulation analysis was carried out using the MiTraS virtual testing platform, considering two realistic driving scenarios. Results confirm the robustness and safety of the proposed control architecture in ensuring the tracking of the desired trajectory while optimising the energy consumption.

Open-Source Tools for Road User Safety Assessment from the VIRTUAL Project

In the assessment of road user and vehicle occupant safety, physical testing is limited to a few scenarios. Virtual testing (VT) offers an opportunity to advance transport safety by introducing additional test cases. The objective of the VIRTUAL project is to provide tools such as finite element models, guidelines and a corresponding platform to foster the uptake of VT. A VT platform, OpenVT, has been established and provides open-source human body models (HBMs) of both an average female and male, seated and standing, as well as a seat, generic vehicle and tram front models. The tool chain from virtual to physical testing has been illustrated in the low severity impact case where the seat evaluation tool was developed. The newly established organisation OVTO will run the OpenVT platform in the future and govern the evolution of the results of the VIRTUAL project after its completion.

Designing a 3D virtual test platform for evaluating prosthetic knee joint performance during the walking cycle

AbstractThis article introduced a three-dimension CAD model of a prosthesis testing platform using SolidWorks software to conduct a kinematic and dynamic analysis of the transfemoral prosthesis of the virtual model. Concurrently, the event-based motion simulation (EBMS) procedure was carried out on the CAD model. The concept of the operational strategy of the test platform was clarified through the machine’s real-life experience before being constructedin vitro. The platform model is capable of reproducing two active movements to simulate the locomotion of the thigh angle and hip vertical displacement for assessing the artificial knee angle motion during the gait cycle. These motions were controlled by two rotary forces (motors) that are utilized to implement control actions in EBMS. The prosthetic knee joint was built with a single axis that performs flexion and extension via the axial force of the spring. The simulation results of the thigh angle motion ranged from20°2{0}^{^\circ }to−15°-1{5}^{^\circ }, while the maximum flexion of the prosthetic knee joint was (46°4{6}^{^\circ }). The mean absolute error was (2.727°2.72{7}^{^\circ }) and (8.338°8.33{8}^{^\circ }) for the thigh and knee joints, respectively. In conclusion, the findings can be utilized to facilitate the design and development of prostheses.

A Review of Intelligent Connected Vehicle Cooperative Driving Development

With the development and progress of information technology, especially V2X technology, the research focus of intelligent vehicles gradually shifted from single-vehicle control to multi-vehicle control, and the cooperative control system of intelligent connected vehicles became an important topic of development. In order to track the research progress of intelligent connected vehicle cooperative driving systems in recent years, this paper discusses the current research of intelligent connected vehicle cooperative driving systems with vehicles, infrastructure, and test sites, and analyzes the current development status, development trend, and development limitations of each object. Based on the analysis results of relevant references of the cooperative control algorithm, this paper expounds on vehicle collaborative queue control, vehicle collaborative decision making, and vehicle collaborative positioning. In the case of taking the infrastructure as the object, this paper expounds the communication security, communication delay, and communication optimization algorithm of the vehicle terminal and the road terminal of intelligent connected vehicles. In the case of taking the test site as the object, this paper expounds the development process and research status of the real vehicle road test platform, virtual test platform, test method, and evaluation mechanism, and analyzes the problems existing in the intelligent connected vehicle test environment. Finally, the future development trend and limitations of intelligent networked vehicle collaborative control system are discussed. This paper summarizes the intelligent connected car collaborative control system, and puts forward the next problems to be solved and the direction of further exploration. The research results can provide a reference for the cooperative driving of intelligent vehicles.

Architecture design of virtual integration test platform for civil aircraft based on ED-247 specification

In typical aircraft virtual integration test of distributed architecture, the interactive communication between virtual components and virtual components, virtual components and hardware, and their real-time scheduling are very important. Based on the programmed ED-247 specification, a virtual bus communication network is constructed, and then a virtual integrated test platform for civil aircraft with abilities of distributed co-scheduling and virtual interaction is provided. With this platform, the traditional physical communication architecture based on reflective memory network could be replaced. While saving the cost of platform construction, it has the ability to carry out various tests such as model-in-the-loop, software-in-the-loop and hardware-in-the-loop. It provides a modular, flexible and automated virtual integrated test environment that can be applied for integration tests during civil aircraft development. Under this integrated architecture, by rapid integration of various versions of simulation models, prototype software and hardware in the development process, rapid validation & verification and prototype iteration can be realized, errors and defects can be found in the early stage of development, thus product design maturity can be rapidly improved, development cycle can be shorten, project cost can be reduced.

Decentralized cooperative crossing at unsignalized intersections via vehicle-to-vehicle communication in mixed traffic flows

Connected Autonomous Vehicles (CAVs) are going to share the road environment with human drivers until their full market deployment achievement. In this context, this paper tackles and solves the problem of decentralized crossing at unsignalized intersections for mixed traffic flows, composed of both connected human-driven vehicles (CHVs) and CAVs. To this aim, a novel cooperative fully-distributed control protocol for CAVs is proposed, augmenting the Adaptive Cruise Control (ACC) action based on proximity sensors measurements, with an additional networked protocol exploiting Vehicle-to-Vehicle (V2V) information for the cooperative evaluation of the Time-to-Intersection of all incoming vehicles within the communication range. This further collaborative action automatically adapts the CAVs motion at intersection avoiding both collisions with other vehicles and intersection deadlocks, while improving the intersection throughput. Safety and mobility performances are evaluated via the purposely designed Virtual Testing platform - Mixed Traffic Simulator (MiTraS)- combining the Matlab/Simulink environment with the SUMO traffic simulator. The analysis is carried out for an exemplary two-lane four-way unsignalized intersection considering both different traffic demands and different CAVs penetration rates. The unavoidable presence of variable delays in information delivery due to the wireless communication network has been also explicitly accounted for in both control design and validation. The extensive simulation analysis confirms how the inclusion of CAVs, equipped with the proposed control algorithm, within the mixed traffic flow strongly improves both the safety and mobility performances of the intersection. Lastly, we disclose how the benefits of the proposed controller increase with CAV penetration.

Examining virtual driving test performance and its relationship to individuals with HIV-associated neurocognitive disorders.

SignificanceExisting screening tools for HIV-associated neurocognitive disorders (HAND) are often clinically impractical for detecting milder forms of impairment. The formal diagnosis of HAND requires an assessment of both cognition and impairment in activities of daily living (ADL). To address the critical need for identifying patients who may have disability associated with HAND, we implemented a low-cost screening tool, the Virtual Driving Test (VDT) platform, in a vulnerable cohort of people with HIV (PWH). The VDT presents an opportunity to cost-effectively screen for milder forms of impairment while providing practical guidance for a cognitively demanding ADL.ObjectivesWe aimed to: (1) evaluate whether VDT performance variables were associated with a HAND diagnosis and if so; (2) systematically identify a manageable subset of variables for use in a future screening model for HAND. As a secondary objective, we examined the relative associations of identified variables with impairment within the individual domains used to diagnose HAND.MethodsIn a cross-sectional design, 62 PWH were recruited from an established HIV cohort and completed a comprehensive neuropsychological assessment (CNPA), followed by a self-directed VDT. Dichotomized diagnoses of HAND-specific impairment and impairment within each of the seven CNPA domains were ascertained. A systematic variable selection process was used to reduce the large amount of VDT data generated, to a smaller subset of VDT variables, estimated to be associated with HAND. In addition, we examined associations between the identified variables and impairment within each of the CNPA domains.ResultsMore than half of the participants (N = 35) had a confirmed presence of HAND. A subset of twenty VDT performance variables was isolated and then ranked by the strength of its estimated associations with HAND. In addition, several variables within the final subset had statistically significant associations with impairment in motor function, executive function, and attention and working memory, consistent with previous research.ConclusionWe identified a subset of VDT performance variables that are associated with HAND and assess relevant functional abilities among individuals with HAND. Additional research is required to develop and validate a predictive HAND screening model incorporating this subset.

Millimeter-Wave Radar in-the-Loop Testing for Intelligent Vehicles

Intelligent vehicle testing and validation technology is a hotspot in the field of intelligent vehicles. Millimeter-wave radar has been widely used in intelligent vehicles and advanced driving assistant systems (ADASs). Owing to low efficiency, high maintenance cost and limited scenario types, the traditional real-vehicle-testing can make it difficult to meet the requirements of intelligent vehicle testing. Also, the degree of reality of millimeter-wave radar sensor models in the virtual test platform is not convincing enough. To solve the mentioned problems, the millimeter-wave radar in-the-loop (mmRil) testing for intelligent vehicles is proposed in this study. First, the radar echo simulation method is developed. Next, based on the millimeter-wave flight time, Doppler frequency shift and the radar power attenuation equation, the mmRil test system is built. A geometric model of a radar target detection and a power attenuation model under bad weather conditions are established. Then, the accuracy of the testbench is verified. Finally, a typical intelligent vehicle control strategy is used for testing under various working conditions and bad weather using the mmRil testbench. The test results show that the mmRil testing has higher authenticity and accuracy than the simulation testing and can be used to test the intelligent vehicle algorithms under severe weather conditions. Compared with the real vehicle testing, the mmRil testing has higher efficiency, repeatability and safety. Therefore, the mmRil testing represents an indispensable testing method in the field of intelligent vehicle testing.

Virtual subjective and objective evaluation method of traffic jam assist

The virtual subjective and objective evaluation method is a significant development method to improve the performance of Traffic Jam Assist (TJA). This paper proposed a virtual subjective and objective evaluation method of TJA, including test scenarios and evaluation indices. Firstly, the paper built a virtual test and evaluation platform for intelligent vehicles based on a high-fidelity driving simulator and VTD traffic simulation software. Secondly, the paper proposed an objective evaluation system composed of evaluation indices, 11 test scenarios, and 49 test cases. Thirdly, the paper put forward a subjective evaluation system composed of three indices: acceptance, comfort, and psychological load. Finally, the paper used the platform mentioned above to conduct subjective and objective tests and evaluations of the TJA system that comes from Matlab. Meanwhile, objective and subjective evaluation scoring results were obtained. The evaluation results showed that the subjective and objective evaluation method proposed in this paper can test the objective and subjective performance of the TJA system comprehensively and systematically, which provided a guarantee for the improvement of the TJA system.

Research on Digital Manufacturing of Lithium Battery Pilot Production Line Based on Virtual Reality

In order to systematically study and verify the digital manufacturing archit ecture and its key technologies, to solve the problems that enterprises currently face in the process of transformation and upgrading of digital and network manufacturing, a lithium battery pilot production line was selected as the research object, using the virtual reality technology as the underlying foundation, integratedly tested and verified the technology contents of the production line including the virtual simulation technology, manufacturing execution construction, information acquisition, and equipment automated transformation required for the construction of a digital factory, tested and verified the inter-drive and mutual control of the pilot line digital twin with its physical entity. The results show that virtual reality technology can provide a virtual testing platform for digital manufacturing which improves the efficiency of automation transformation, digital production and network operation of the actual production lines. This can provide a useful reference for enterprises to achieve a higher degree of digital manufacturing and maintenance in the future.

A virtual test platform for railway draft gear designs

A virtual test platform for railway draft gear designs

A virtual test platform for railway draft gear designs

Draft gear design and assessment processes commonly use results from physical drop-hammer tests, vehicle impact tests and laboratory rig tests which all utilise quite different impact velocity rang...

Progressive delamination of laminated composites via 1D models

This paper presents a novel numerical framework to simulate the progressive delamination in laminated structures based on 1D component-wise models. The proposed numerical tool is a part of the virtual testing platform built within the Carrera Unified Formulation, a hierarchical, higher-order structural framework to generate theories of structures via a variable kinematic approach. Formulated within the Lagrange polynomial CUF models, the component-wise approach models the components of a complex structure through 1D CUF models at reduced computational costs and 3D-like accuracies. The effectiveness of CUF-CW models to capture accurate 3D transverse fields are of interest to solve delamination problems by integrating a class of higher-order cohesive elements to simulate the cohesive mechanics among the various components of the structure. The present framework adopts a bilinear constitutive law based on the mixed-mode delamination propagation and an efficient arc-length solver based on an energy-dissipation constraint. The numerical results aim to verify the accuracy and computational efficiency of CUF-CW models through benchmark composite delamination problems including multiple delamination fronts and comparisons with reference literature solutions and standard 3D FEM models. The outcomes show multi-fold improvements in the analysis times, good matches with experimental results, and promising enhancements of the meshing process due to the absence of aspect ratio constraints.

Application and comparative analysis on three dimensional camera measurement system in full size inspection of batch production parts

Box-type parts are the basic parts of general machines, they assemble the shaft, sleeve, gear and other related parts of the machine into a whole, so as to maintain the correct mutual position accuracy between the parts. Their complex forming structure, large matching dimensions and high precision requirements directly affect the accuracy, performance and life of the machine. Aiming at the problems of large size and low efficiency of single piece inspection for box parts, this paper takes the spindle box of horizontal lathe as the research object, simulates through virtual testing platform, puts several parts of the same box parts in a certain order, determines the appropriate angle and shoots batch parts placement model in many directions, and adopts three-dimensional method. The camera measurement system detects the full size of the same batch of products and obtains the test results. On this basis, the traditional laser tracking measurement method is used to detect and compare the randomly selected single spindle box. The comparison results show that the three-dimensional camera measurement method can detect the forming accuracy of batch box parts well under the appropriate position and photographic angle, and the full-scale measurement error can be effectively controlled within the technical allowable range. This study provides a preliminary basis for the three-dimensional camera measurement technology in improving the efficiency and accuracy of full-scale measurement of batch box parts.

Virtual site acceptance test platform for IEC 61850 based substations with multi‐vendor bay solutions

IEC 61850 conformance alone does not necessarily guarantee interoperability of devices from different manufacturers. Achieving full interoperability in a substation protection and control system involving different vendors will increase the confidence of power utilities to deploy digital bays or substations on site. This study presents the development of a virtual site test platform to assess the engineering process and interoperability performance for a fully digital substation with multi-vendor bay solutions. A data monitoring tool has been developed to visualise data flows in IEC 61850 networks, which can help commissioning engineers to intuitively validate signals like they do for conventional schemes. Case studies are presented to investigate the interoperability of sampled values, generic object oriented substation events and manufacturing message specification communication services. The learning from the system integration and testing will help utilities identify potential issues in engineering phases and hence reduce the risks associated with future site tests.

An Evaluation Strategy of Spacecraft Test Case Adequacy Based on Mutation Testing

As typical safety-critical system, the trustworthiness of spacecraft has become a widespread concern. The evaluation of trustworthiness depends on the execution of spacecraft test cases, of which the adequacy is of great importance for the spacecraft to conduct effective assessment of trustworthiness. This paper focuses on the evaluation of the adequacy of spacecraft test cases based on mutation testing technique. Mutation testing theory is extended to spacecraft testing, and mapping between spacecraft faults and mutation operators is constructed. A virtual spacecraft testing platform is developed, on which the spacecraft fault injection strategy is given and test cases generated by IPOG algorithms are evaluated by adequacy, verifying the effectiveness of the proposed strategy.

Artificial Blood Glucose Control using a DDE Modelling Approach

In this paper we consider the problem of artificial blood glucose control for a type 1 diabetic using delay differential equations to model the glucose metabolism. This model is obtained by considering an adjustment of the minimal model of Bergman. In order to design a controller which can stabilize blood glucose in a safe range, the design of a robust model predictive controller is considered. The various uncertainties and disturbances are introduced through the introduction of perturbed parameters. Finally, the performances of the controller are exemplified on an approved virtual testing platform showing the good properties of the developed controller.

Research on Network Virtual Instrument

According to research on the technologies of virtual instrument and network, a netwok virtual instrument test structure based on mixed C/S/B mode is presented in this paper. In order to solve the problem of real-time of network test, ActiveX client control and instrument testing application server is developed based on ActiveX plug-in technology. Users can login the virtual instrument test platform through the browser, submit request commands and test parameters to the Web server, control the remote equipments, and observe the real-time test data and analysis results.