Prototype Simulation Research Articles

Dynamic characteristics and transmission efficiency of energy-harvesting shock absorber with low speed and heavy duty capacity

Traditional hydraulic shock absorbers commonly encounter challenges such as cavitation, oil leakage, and the management of energy dissipation. The proposed regenerative shock absorber, which utilizes a ball screw mechanism, offers advantages such as high efficiency and heavy load capacity. This paper focuses on the design, modeling, and testing of a mechatronic shock absorber. Virtual prototype simulation techniques are employed to investigate the dynamic behaviors of the shock absorber. The paper presents a systematic efficiency model of a shock absorber, which is based on the ball screw and gearbox mechanisms. The study comprehensively analyzes the effects of rotation speed, axial load, and structure parameters on transmission efficiency. The results demonstrate that a peak power of 38 W can be achieved with a damping force of only 340 N, and the recovery efficiency can reach up to 28%. The experimental test results validate the effectiveness and reliability of the proposed dynamic and efficiency models. The originality of this study lies in the development of a novel energy-harvesting shock absorber with a ball screw mechanism in series with a gearbox, which shows excellent energy recovery potential and transmission efficiency under low speed and high duty conditions.

Research on coal rock parameter calibration based on discrete element method

To ensure that the discrete element model of the coal wall accurately reflects the actual cutting process of coal and rock during virtual prototype simulation of mining equipment, this study aims to expedite the development of intelligent mining machinery. Using coal samples from the 4602 working face of Yangcun Coal Mine, operated by Yanzhou Coal Mining Group, we conducted coal rock packing experiments and uniaxial compression tests to obtain the packing angle and compressive strength of the coal samples. Based on the experimental results, we designed Plackett–Burman experiments (PB experiments), steepest ascent experiments, and Box-Behnken experiments to study the influence of particle contact mechanics parameters and bonding mechanics parameters on the packing angle and compressive strength, using the packing angle and compressive strength as response variables. Our objective is to minimize the relative error between the simulated packing angle and the measured packing angle. We solved and optimized the parameter calibration model and conducted simulation calibration experiments based on the optimization results. A comparative analysis with the actual test results revealed that the maximum relative errors between the simulated and measured values for the packing angle and compressive strength were only 2.9% and 5.0%, respectively. Additionally, a discrete element model of a typical working face coal wall was established based on the parameters obtained from this calibration method. A bidirectional coupling model of the cutting process between the coal and rock was created using EDEM-RecurDyn to simulate the rigid-flexible coupling of the coal cutter. An experimental coal wall model was constructed based on similarity theory, and both simulation and physical experiments were conducted. The evaluation metrics for comparison were the time-domain and frequency-domain characteristics of the drum’s vibration signals. The maximum relative error for the time-domain signal characteristics between the two experimental setups was only 4.19%, while the maximum relative error for the frequency-domain signal characteristics was 3.75%. This validates the feasibility of the proposed calibration method for the discrete element coal wall model and the accuracy of the calibration results. Furthermore, it demonstrates that the constructed discrete element coal wall accurately represents the actual coal and rock properties. The virtual simulation based on this model effectively replicates the interaction process between mining machinery and coal, providing a safe, efficient, and low-cost technological approach for performance analysis of mining equipment and intelligent control of supporting devices.

Stability analysis of micro-probe landings in complex terrain

Abstract Addressing the problem of landing stability of the micro-probes on the surface of extraterrestrial objects, combined with the geometric properties of the orthotetrahedron, this paper proposes a structural design method of the four-spine microprobe landing bracket that can adapt to the complex terrain and carries out the analysis of the landing stability of the four-spine bracket under the state of three-legged landing and the optimization of the structure for combined terrain of stones and slopes. Referring to the ZMP theory, the harsh working conditions of the four-spine bracket when landing are sorted out and determined. Based on the kinematics theory, the collision mechanism between the four-spine bracket and the ground is analyzed, and a landing model suitable for the micro-probes is established, which provides the basis for determining the landing stability of the micro-probe. Around the collision mechanism and landing model, the dimension optimization of the four-spine bracket is carried out, and the results of Adams dynamics simulation analysis and prototype test show that the landing stability of the four-spine bracket is improved, which verifies the validity of the optimization idea.

Variable Admittance Control of High Compatibility Exoskeleton Based on Human–Robotic Interaction Force

The wearable exoskeleton system is a typical strongly coupled human–robotic system. Human–robotic is the environment for each other. The two support each other and compete with each other. Achieving high human–robotic compatibility is the most critical technology for wearable systems. Full structural compatibility can improve the intrinsic safety of the exoskeleton, and precise intention understanding and motion control can improve the comfort of the exoskeleton. This paper first designs a physiologically functional bionic lower limb exoskeleton based on the study of bone and joint functional anatomy and analyzes the drive mapping model of the dual closed-loop four-link knee joint. Secondly, an exoskeleton dual closed-loop controller composed of a position inner loop and a force outer loop is designed. The inner loop of the controller adopts the PID control algorithm, and the outer loop adopts the adaptive admittance control algorithm based on human–robot interaction force (HRI). The controller can adaptively adjust the admittance parameters according to the HRI to respond to dynamic changes in the mechanical and physical parameters of the human–robot system, thereby improving control compliance and the wearing comfort of the exoskeleton system. Finally, we built a joint simulation experiment platform based on SolidWorks/Simulink to conduct virtual prototype simulation experiments and recruited volunteers to wear rehabilitation exoskeletons to conduct related control experiments. Experimental results show that the designed physiologically functional bionic exoskeleton and adaptive admittance controller can significantly improve the accuracy of human–robotic joint motion tracking, effectively reducing human–machine interaction forces and improving the comfort and safety of the wearer. This paper proposes a dual-closed loop four-link knee joint exoskeleton and a variable admittance control method based on HRI, which provides a new method for the design and control of exoskeletons with high compatibility.

Design and analysis of a thick-panel origami-inspired soft crawling robot with multiple locomotion patterns

Abstract Due to the flexibility obtained through both materials and structures, soft robots have wide potential applications in complicated internal and external environments. This paper presents a new soft crawling robot with multiple locomotion patterns that integrate inchworm motion and various turning motions. First, the conceptual design of the proposed robot is presented by introducing thick-panel origami into the synthesis of a crawling robot, resulting in a Waterbomb-structure-inspired hybrid mechanism. Second, all locomotion patterns of the robot are precisely described and analyzed by screw theory in an algebraic manner, which include inchworm motion, restricted planar motion, quantitative turning motion, and marginal exploration motion. Then, the output motion parameter for each locomotion pattern is analytically modeled as a function of the robotic dimensional parameters, and the robot can thus be designed and controlled in a customized way for the expected output motion. Finally, the theoretical analysis and derivations are validated by simulation and physical prototype building, which lay the foundations for the design and manufacture of small-scale soft crawling robots with precise output motions in a complex planar environment.

PID PATH FOLLOWING CONTROL SYSTEM DESIGN ON UNMANNED AUTONOMOUS FORKLIFT PROTOTYPE

One of the technologies often used in material handling and material transport is forklift. Conventionally forklifts are operated by human operators. For efficiency, to improve security, safety, and occupational health and to minimize the risk of operators, forklifts can be automated. Therefore, the idea of unmanned autonomous forklift innovation was introduced. In this final project, a motion control system was designed for an unmanned autonomous forklift prototype both in simulation and hardware using PID control techniques, and the odometry system was equipped with a rotary encoder. In the simulation, the controlled variable was the distance and the manipulated variable was the force on the vehicle. Meanwhile, in the prototype, the controlled variable was distance and the manipulated variable was the motor pulse. In the simulation stage the PID control parameters were applied . with an error of 0.32% in the simulation. The PID control parameters were applied to the prototype, that is, . The distance tests were done with variation of 50 cm to 200 cm (25 cm intervals). One variation of the distance experiment was done 5 times. The average absolute error resulted was 2.36 cm.

A novel interleaved BIFRED-Zeta with intelligent MPPT for PV applications

ABSTRACT The current energy perspective postulates profound presence of Renewable Energy Sources (RESs), resulting in need for optimal DC-DC converter design to assure efficient power conversion and minimise losses. By minimising energy losses and improving power quality, an optimal converter design helps ensure a stable and reliable power supply from RESs, which is essential for meeting the growing demand for clean energy. Therefore, this research introduces an innovative Interleaved BIFRED-Zeta converter configuration, designed to meet all criteria associated with an optimal converter design. The interleaved architecture of converter allows the reduction of current ripples and voltage stress along with the improvement of efficiency. Furthermore, the absence of transformer in converter structure enables it to be simple, cost effective and less bulky. The Interleaved Boost Integrated Flyback Rectifier Energy Storage DC-DC (BIFRED)-Zeta converter duty cycle is adjusted continuously using Cascaded Artificial Neural Network (ANN) Maximum Power Point Tracking (MPPT) to further maximise Photovoltaics (PV) system power output. The capability of suggested converter design is demonstrated by the results obtained using simulation and laboratory prototype implementation. Thereby, a peak efficiency of 97.6% is estimated to be achieved using suggested converter design.

Data-driven simulation methodology for exploring optimal storage location assignment scheme in warehouses

Storage location assignment effects the efficiency of order picking, and thus it is significant for improving operation management in warehouses. Due to the dynamic nature of order picking, system simulation has been recently used for solving Storage Location Assignment Problem (SLAP). However, most previous studies aimed at using simulation to evaluate and verify the optimum storage schemes obtained from mathematical programming, which belongs to “optimize first and then simulation” in essence. In this context, we proposed a novel data-driven simulation methodology for solving SLAP in this study. A four-quadrant judgment criterion is proposed to guide storage locations assignment based on correlation and turnover frequency of items. Moreover, trajectory and blocked heatmaps are involved for exploring the contribution of different factors to order picking efficiency through scenario experiments. A prototype simulator was then developed and applied in a case study to demonstrate its utility. The results obtained reveals the fact that congestion blocking is another key factor impacting global order picking efficiency, and thus considering the correlation between items in storage schemes designing may not always improve the system performance due to the accompanying increases of blocking intensity during the dynamic order picking processes. The findings also demonstrate our inference that the priority of turnover frequency-based storage policy should be higher than correlation between items in designing storage schemes. This work provides new perspectives and valuable demonstration on the evaluating the contribution of different factors to global order picking efficiency as well as exploring optimal storage schemes through emerging data-driven simulation paradigm.

Research on the Design Method of Camellia oleifera Fruit Picking Machine

Camellia oleifera fruit pickers are essential for improving picking efficiency and promoting the Camellia oleifera industry. However, it is challenging to develop pickers that meet user needs. Current design tools and methods have limitations, such as a single model, poor synergy between integrated models, and subjective bias when analysing user requirements and translating them into product attributes. To solve these problems, this study proposes a new design decision model based on the Fuzzy Analytic Hierarchy Process (FAHP), Function Analysis System Technique (FAST), Theory of Inventive Problem Solving (TRIZ Theory), and extension transformation theory. The model was developed and applied to design an Camellia oleifera fruit picker. In this paper, an empirical investigation of an Camellia oleifera base in Wuhan was carried out, and multi-level demand analysis was used to identify the design demands in the behavioural process; FAHP was used to calculate the demand weights to clarify the design focus; expert knowledge was used to convert the demands into specific product functional features, and FAST was used to decompose these features to find the contradictory conflicts; TRIZ theory was used to determine the principles of resolving the contradictions, and the extension transformation theory were used to generate the creative design solutions for the products. By integrating FAHP, FAST, TRIZ theory and the extension transformation theory, the subjective bias in product design is eliminated, the design decision-making process is improved, and new methods and ideas are provided for the design of oleaginous tea fruit pickers and similar products. Finally, the conceptual design of an Camellia oleifera fruit picking machine was produced. However, the conceptual design has yet to be subjected to exhaustive simulation experiments and prototype testing. Future research will focus on conducting the necessary simulations, prototypes, and field tests to fully assess the feasibility and effectiveness of the design and make the required iterative improvements accordingly to commercialize the product eventually.

Virtual prototype modeling and fuzzy control of the heave compensation system for a 500-ton deep-sea mining vessel

The unexpected heave motion of vessels generated by waves has always threatened the safe operation of mining vessels. The heave compensation system is a critical equipment for offshore cranes to ensure the safety and stability of the deep-sea mining vessel operation. Unfortunately, the nominal load of the mining vessel transporting minerals has become increasingly large, which has led to the dynamic performance of the heave compensation decline and a significant increase in energy consumption. To solve these problems, a semiactive heave compensation system and fuzzy logic-based controller are proposed in this paper. First, an active-passive hybrid heave compensation system is designed to reduce energy consumption greatly. The virtual prototype models of the proposed heave compensation system in a 500-ton deep-sea mining vessel are also built. Then, an adaptive tuning PID controller is developed based on the Transfer function of the heave compensation system and Mamdani-type fuzzy logic. Virtual prototype simulation results of AMESim-Simulink joint simulation illustrate that the accuracy of compensation for the four or six sea states reaches more than 90% with the proposed method and the power of the active compensation system is about 21% of the total power. Finally, the experimental results are included to demonstrate the effectiveness of the proposed semiactive heave compensation system.

Dynamics for rigid–flexible coupled solar panel multibody system composed of composite laminated plates

Composite laminates are widely employed in the fabrication of solar panels in modern spacecraft engineering because of their superior durability, mechanical qualities, and cost-effectiveness. This research is dedicated to multibody system dynamics modeling of composite laminate solar panels, specifically the coupling system between the rigid main body and the flexible solar panels. In this study, the rigid body is modeled using the natural coordinate formulation (NCF), and for the flexible solar panel, the absolute nodal coordinate formulation (ANCF) with a 36-DOF reduced-order composite thin shell element is used to accurately capture the coupling effect of the solar panel under large motion and deformation. Compared to a 48-DOF fully parameterized thick plate element, this method efficiently avoids shear locking and improves numerical solution convergence efficiency. Based on the Kirchhoff theory and the constitutive relationship of composite laminates, a dynamic model of the multibody system is developed, taking into account the rigid-flexible coupling effect and the kinematic constraints. This work thoroughly discusses the dynamic behavior of solar panel deployment using a comparative analysis of numerical simulation and virtual prototype simulation, and the accuracy is verified. The findings indicate that the flexible characteristics and fiber orientation of composite laminates have a significant impact on the dynamic response of solar panels during deployment. Furthermore, the bang-bang attitude controller is designed, and the difference in dynamic response between the two modeling methods in controlled and uncontrolled states is studied, providing an important theoretical foundation and technical support for solar panel design and analysis.

Towards Double-Layer Dynamic Heterogeneous Redundancy Architecture for Reliable Railway Passenger Service System

Researchers have proposed the dynamic heterogeneous redundancy (DHR) architecture, which integrates dynamic, heterogeneous, redundant, and closed-loop feedback elements into the system, to fortify the reliability of the railway passenger service system (RPSS). However, there are at least two weaknesses with the common DHR architectures: (1) they need system nodes with enough computing and storage resources; (2) they have hardly considered the reliability of DHR architecture. To this end, this paper proposes a double-layer DHR (DDHR) architecture to ensure the reliability of RPSS. This architecture introduces a set of algorithms, which are optimized co-computation and ruling weight optimization algorithms for the data processing flow of the DDHR architecture. This set improves the reliability of the DDHR architecture. For the evaluation of the reliability of DDHR architecture, this paper also proposes two metrics: (1) Dynamic available similarity metric. This metric does not rely on the overall similarity of the double-layer redundant executor sets but evaluates the similarity of their performance under the specified interaction paths within a single scheduling cycle. The smaller its similarity, the higher its reliability. (2) Scheduling cycle under dual-layer similarity threshold. This metric evaluates the reliability of the RPSS under actual conditions by setting the schedulable similarity thresholds between the same and different layers of the dual-layer redundant executives in the scheduling process. Finally, analog simulation experiments and prototype system building experiments are carried out, whose numerical experimental results show that the DDHR architecture outperforms the traditional DHR architecture in terms of reliability and performance under different redundancy and dynamically available similarity thresholds, while the algorithmic complexity and multi-tasking concurrency performance are slightly weaker than that of the DHR architecture, but can be applied to the main operations of the RPSS in general.

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3D Model Prototype of Robotic Arm and Motion Control Simulation on 4-DOF Based on Virtual Reality

Penggunaan robotika dalam industri modern telah menjadi krusial, terutama dalam otomatisasi dan manufaktur. Robot lengan, sebagai elemen kunci, memerlukan pengembangan dan pengujian prototipe yang teliti untuk mencapai performa optimal. Teknologi Virtual Reality (VR) muncul sebagai solusi inovatif untuk mensimulasikan gerakan robot lengan di lingkungan virtual, memungkinkan visualisasi dan interaksi mendalam dalam berbagai derajat kebebasan (DOF). Penelitian ini bertujuan untuk membangun prototype model robot lengan 3D dan mengerjakan eksplorasi virtualisasi gerakan dari pengembangan prototipe robot lengan berbasis VR. Hasil penelitian ini diantaranya telah dilakukan integrasi teknologi VR dengan sistem kontrol robot lengan dalam lingkungan Unity, memungkinkan pengguna mengendalikan gerakan robot lengan dalam ruang 3D secara real-time. Studi ini menunjukkan bahwa robot lengan dengan 4 DOF dapat mencapai fleksibilitas dan presisi yang diinginkan pada skenario uji yang telah dirancang. Dari hasil pengujian antara parameter simulasi dari lingkungan unity dan perhitungan secara teoritis gerakan robot lengan yang dikendalikan menggunakan controller, diperoleh rentang koordinat yang dijangkau adalah x = -19,85 cm hingga 28,53 cm, y = 21,69 cm hingga 52,04 cm, z = -15,35 cm hingga -24,87 cm. Setelah dilakukan perhitungan perbandingan antara hasil pengujian di Unity dan hasil perhitungan berdasarkan rumus, didapatkan selisih koordinat sebesar x = 0,080, y = 0,038, dan z = 0,034

From data to action in flood forecasting leveraging graph neural networks and digital twin visualization

Forecasting floods encompasses significant complexity due to the nonlinear nature of hydrological systems, which involve intricate interactions among precipitation, landscapes, river systems, and hydrological networks. Recent efforts in hydrology have aimed at predicting water flow, floods, and quality, yet most methodologies overlook the influence of adjacent areas and lack advanced visualization for water level assessment. Our contribution is two-fold: firstly, we introduce a graph neural network model (LocalFLoodNet) equipped with a graph learning module to capture the interconnections of water systems and the connectivity between stations to predict future water levels. Secondly, we develop a simulation prototype offering visual insights for decision-making in disaster prevention and policy-making. This prototype visualizes predicted water levels and facilitates data analysis using decades of historical information. Focusing on the Greater Montreal Area (GMA), particularly Terrebonne, Quebec, Canada, we apply LocalFLoodNet and prototype to demonstrate a comprehensive method for assessing flood impacts. By utilizing a digital twin of Terrebonne, our simulation tool allows users to interactively modify the landscape and simulate various flood scenarios, thereby providing valuable insights into preventive strategies. This research aims to enhance water level prediction and evaluation of preventive measures, setting a benchmark for similar applications across different geographic areas.

High-Definition Dynamic Voltage Restorer Systems Using Equivalent Time Sampling Techniques and Circular Structural Memory Filters

Due to advances in power electronics technology and the evolution of automation devices, the number of electrical devices that are sensitive to power quality is rapidly increasing, and for this reason, users are increasing their demand for high quality. To meet power quality demands, many power conversion devices are used, including dynamic voltage restorers (DVRs). DVRs are recognized as devices that can effectively manage problems such as voltage segments, swells, and harmonics. DVR control requires many samples for harmonic compensation, which has the disadvantage of being complicated to implement due to fast digital signal processing computation and the application of the cyclic discrete Fourier transform. In this paper, a high-precision DVR system configuration is proposed that compensates for harmonics using a periodically equivalent time-interval sampling technique and a novel circular-structured memory filter. The proposed circular-structured multi-pointer memory filter is an effective filter algorithm for high-precision input voltage measurement because it can remove noise and compensate for the delay of the phase angle of the filter in voltage measurement. A simulation and DVR prototype system were built, and the feasibility and effectiveness of the phase angle multi-filter voltage detection method and the compensation method were verified by experiments.

Terrestrial locomotion stability of undulating fin amphibious robots: Separated elastic fin rays and asynchronous control

To address the problem of poor postural stability in an undulating fin robot during terrestrial locomotion, this study proposes a novel design featuring separate elastic fin rays with an asynchronous control scheme for bilateral fin surfaces. In this scheme, the robotic fin ray structure and surface driving mode are innovatively designed to mitigate the pitch-angle instability caused by adverse factors, such as integral rigid fin rays and synchronized fin surfaces. Expanding on the ground dynamics model of the robot, this study examined the variation in the pitch angle of the robot body. In this study, an innovative design with separated elastic fin rays was proposed and their feasibility was validated through finite element simulations. In addition, a virtual simulation prototype of the robot was developed to verify the robot body stability under asynchronous fin surface control. The simulation results show that separate elastic fin rays and asynchronous control can effectively improve the postural stability of robots in terrestrial locomotion. In this study, a robot prototype was tested experimentally in various terrestrial environments. The experimental results indicate that equipping the robot with separated elastic fin rays and employing asynchronous motion control significantly enhances the motion postural stability across typical terrain conditions. The maximum pitch angle range can be reduced by 42.7–52.4%, providing new insights for the design of amphibious robots with undulating fins.

Research on the Construction Technology of INS Digital Prototype Based on Digital Twin

In response to the continuous advancement of digitalization and intelligence in equipment as mandated by the state, a digital twin-based inertial navigation digital prototype construction scheme has been designed. This scheme supports the realization of intelligent manufacturing, testing, evaluation, and operational assurance throughout the lifecycle of inertial navigation products. This paper decomposes the physical entities of the " three-autonomy " SINS and integrates component-level inertial navigation digital prototypes based on the principles of inertial navigation. The prototypes were integrated using heterogeneous models in simulation software. Pure navigation functionality verification was conducted on the prototypes. The results show that the errors in pure simulation of the inertial navigation digital prototypes constructed in this study are consistent with the physical navigation results of inertial navigation systems, providing a reference for the development of inertial navigation digital twin systems.

Creation of a prototype simulator object for quality control of bone segmentation algorithms for use in tomographic post-processing software

Considering the growing influence of Artificial Intelligence (AI) in medicine, especially in radiology, and the advances in computational power and theoretical understanding of AI algorithms (MESKÓ; GÖRÖG, 2020), concerns about the reliability of these methods arise. This study developed a prototype simulator object for quality control of bone segmentation algorithms in computed tomography. To achieve this objective, a 3D simulator object was created using advanced printing techniques, with materials that faithfully replicate the density and hardness of human bones, such as RadioMatrix. The results indicated that bone segmentation in post-processing software is strongly influenced by tissue density and that currently available AI models lack explainability (EXAI). The analysis revealed the need for algorithms that consider not only density but also the specific shapes and characteristics of bones. It is concluded that the developed prototype is effective in the evaluation and quality control of bone segmentation algorithms, promoting greater safety in clinical application and better explainability of bone segmentation algorithms in post-processing software for computed tomography.

An improved voltage gain bidirectional DC/DC converter based on voltage multiplier cell for electric vehicle application

ABSTRACT The global energy crisis has raised environmental concerns, leading governments to invest in renewable energy and address electric vehicle (EV) and hybrid EV (HEV) difficulties. One of the main challenges is the interface between the energy storage system and the DC-link of the three-phase inverter. For this aim, an improved voltage gain bidirectional DC/DC converter based on a voltage multiplier cell (VMC) is proposed in this paper, which acts like a high boost converter when the energy storage system is powering the EV and a buck converter when regenerative braking is required. The proposed bidirectional converter has advantages like low device account, simple structure, reduced switching power losses, high voltage gain, common ground, and increased efficiency. An output voltage of 10 times the input voltage in boost mode is provided by the proposed converter. Also, the proposed converter can generate a voltage 0.26 times lower than the input voltage in buck mode. The operating principle and comparative analysis with other existing converters are presented. Moreover, the efficiency calculation is discussed by assuming the non-ideal parameters. The proposed converter has a maximum efficiency of 97.78%. Finally, a 500 W simulation prototype is implemented in PSIM software to confirm the theoretical analysis.