Multibody System Dynamics最新文献_第6页

Combined recurrent neural networks and particle-swarm optimization for sideslip-angle estimation based on a vehicle multibody dynamics model 基于车辆多体动力学模型的循环神经网络和粒子群优化相结合的侧滑角估计方法

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-02-19 DOI: 10.1007/s11044-024-09973-5

Yu Sun, Yongjun Pan, Ibna Kawsar, Gengxiang Wang, Liang Hou

{"title":"Combined recurrent neural networks and particle-swarm optimization for sideslip-angle estimation based on a vehicle multibody dynamics model","authors":"Yu Sun, Yongjun Pan, Ibna Kawsar, Gengxiang Wang, Liang Hou","doi":"10.1007/s11044-024-09973-5","DOIUrl":"https://doi.org/10.1007/s11044-024-09973-5","url":null,"abstract":"The active safety system of a vehicle typically relies on real-time monitoring of the sideslip angle and other critical signals, such as the yaw rate. The vehicle sideslip angle cannot be measured directly due to the high cost and impracticality of sensor networks. The vehicle sideslip can be estimated using kinematic, dynamic, or machine-learning models and available vehicle states. This paper combines recurrent neural networks and the particle-swarm optimization (PSO) algorithm to estimate the vehicle sideslip angle accurately. First, a vehicle-dynamics model is constructed to conduct dynamics simulations of vehicles under various driving conditions and road environments for data collection. Secondly, the obtained vehicle states, including velocity, acceleration, yaw rate, and steering, are used to develop machine-learning models that estimate the vehicle sideslip angle. Two machine-learning models are proposed using the long short-term memory neural network (LSTM) and the bidirectional long short-term memory neural network (BiLSTM). Thirdly, the PSO algorithm is employed to optimize the hyperparameters of the LSTM and BilLSTM models for enhanced estimation precision. The Gaussian noise is added to the datasets to evaluate the robustness of the estimation models. The results indicate that the estimation models are capable of accurately predicting the vehicle’s sideslip angle. The (R^{2}) values of the results are mostly greater than 0.96. The PSO algorithm can improve estimation precision, and the PSO-LSTM model performs the best.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"22 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139924982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chemotherapy for Salivary Gland Malignant Carcinoma : Meta-analysis and Systemic Review. 唾液腺恶性肿瘤的化疗：Meta 分析和系统综述。

IF 2.6 2区工程技术

Multibody System Dynamics Pub Date : 2024-02-01 Epub Date: 2023-08-11 DOI: 10.1007/s12070-023-04104-6

Kritant Bhushan, Mansi Luthra Sharma, Deepak Kumar Gupta

{"title":"Chemotherapy for Salivary Gland Malignant Carcinoma : Meta-analysis and Systemic Review.","authors":"Kritant Bhushan, Mansi Luthra Sharma, Deepak Kumar Gupta","doi":"10.1007/s12070-023-04104-6","DOIUrl":"10.1007/s12070-023-04104-6","url":null,"abstract":" The primary form of treatment for salivary gland cancer is surgical resection. Radiation therapy is used as adjuvant therapy in cases of aggressive tumours, currently patients with recurrent or metastatic cancer who are not suitable for surgery or radiation are most often treated with chemotherapy. PRISMA guidelines for systematic reviews were followed to evaluate salivary gland malignancies involving cytotoxic chemotherapy and biologic agents. An electronic literature search of Medline, PubMed, Scopus, etc. was performed and relevant articles were selected based on the inclusion criteria. Cytotoxic chemotherapies and biologic drugs such as anti HER - 2, anti-EGFR and anti-C-Kit are used to treat salivary gland cancer. Although most trials have respond poorly to standard chemotherapy with short durability and significant toxicity. Most of the research has focused on ACC and the use of combination therapy with cisplastin in conjunction with other treatments has been found to improve overall survival rate. Due to the limited patient population it was difficult to assess the efficacy of chemotherapy, which achieved very modest results. There are potential molecular targets such as HER2,NTRK and targeted treatments are becoming more popular. However to further explore potential treatment alternatives SGC patients should be enrolled in clinical trials.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"31 1","pages":"123-129"},"PeriodicalIF":2.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10908940/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74067037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal-structure interactions on the nonlinear behavior of the heavy-load mechanical press with multiple clearance-induced joints 热与结构相互作用对带有多个间隙感应接头的重型机械压力机非线性行为的影响

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-02-01 DOI: 10.1007/s11044-024-09966-4

Xuze Wu, Yu Sun, Wen Liu, Yu Chen, Ruoda Wang, Yi Qiao, Yu Wang

{"title":"Thermal-structure interactions on the nonlinear behavior of the heavy-load mechanical press with multiple clearance-induced joints","authors":"Xuze Wu, Yu Sun, Wen Liu, Yu Chen, Ruoda Wang, Yi Qiao, Yu Wang","doi":"10.1007/s11044-024-09966-4","DOIUrl":"https://doi.org/10.1007/s11044-024-09966-4","url":null,"abstract":"The thermal elastohydrodynamic (TEHD) effect contributes significantly to the improvement of dynamic behavior of mechanical presses, especially under the complex conditions of high speed, heavy load, and high temperature. In this work, a novel mixed-TEHD model and the numerical algorithm for the multiphysics problem are proposed to predict the nonlinear behavior of the mechanical press considering multiple clearance-induced joints. The propounded lubrication principle includes the thermal effects caused by contact event and the influence of TEHD on the clearance dimension under complex lubrication conditions. The equivalent nodal force method is adapted as the unified treatment of elastic and thermal deformation in the clearance joints. With the introduction of non-conservative forces, the system’s dynamic model is formulated and solved by the Lagrange approach and Newmark-(beta ) integration algorithm, respectively. Numerical simulations are performed considering different fluid viscosities and crank speeds to investigate the nonlinear behavior of the mechanical press under various lubrication conditions. The results demonstrate the significance of frictional contact on the bearing thermal characteristics. Compared to the elastic deformation effect of transmission components, the variation of system position accuracy is primarily governed by the dynamics of mixed-lubricated joints. Furthermore, experimental studies are performed to validate the numerical findings.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"56 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139666704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A discrete adjoint gradient approach for equality and inequality constraints in dynamics 动力学中平等和不平等约束的离散邻接梯度法

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-01-29 DOI: 10.1007/s11044-024-09965-5

Daniel Lichtenecker, Karin Nachbagauer

{"title":"A discrete adjoint gradient approach for equality and inequality constraints in dynamics","authors":"Daniel Lichtenecker, Karin Nachbagauer","doi":"10.1007/s11044-024-09965-5","DOIUrl":"https://doi.org/10.1007/s11044-024-09965-5","url":null,"abstract":"The optimization of multibody systems requires accurate and efficient methods for sensitivity analysis. The adjoint method is probably the most efficient way to analyze sensitivities, especially for optimization problems with numerous optimization variables. This paper discusses sensitivity analysis for dynamic systems in gradient-based optimization problems. A discrete adjoint gradient approach is presented to compute sensitivities of equality and inequality constraints in dynamic simulations. The constraints are combined with the dynamic system equations, and the sensitivities are computed straightforwardly by solving discrete adjoint algebraic equations. The computation of these discrete adjoint gradients can be easily adapted to deal with different time integrators. This paper demonstrates discrete adjoint gradients for two different time-integration schemes and highlights efficiency and easy applicability. The proposed approach is particularly suitable for problems involving large-scale models or high-dimensional optimization spaces, where the computational effort of computing gradients by finite differences can be enormous. Three examples are investigated to validate the proposed discrete adjoint gradient approach. The sensitivity analysis of an academic example discusses the role of discrete adjoint variables. The energy optimal control problem of a nonlinear spring pendulum is analyzed to discuss the efficiency of the proposed approach. In addition, a flexible multibody system is investigated in a combined optimal control and design optimization problem. The combined optimization provides the best possible mechanical structure regarding an optimal control problem within one optimization.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"210 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139581154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic modeling and closed-loop control design for humanoid robotic systems: Gibbs–Appell formulation and SDRE approach 仿人机器人系统的动态建模和闭环控制设计：吉布斯-阿佩尔公式和 SDRE 方法

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-01-18 DOI: 10.1007/s11044-023-09964-y

{"title":"Dynamic modeling and closed-loop control design for humanoid robotic systems: Gibbs–Appell formulation and SDRE approach","authors":"","doi":"10.1007/s11044-023-09964-y","DOIUrl":"https://doi.org/10.1007/s11044-023-09964-y","url":null,"abstract":"<h3>Abstract</h3> Analyzing the walking motion of the bipedal robots that have upper-body parts as well as lower-body legs and exhibit a human-like gait is a challenging task. One of the main objectives of this paper is to present a new and systematic method for designing a desired movement trajectory for a bipedal robot such that it has the greatest conformity with the system dynamics and makes the gait of a bipedal robot similar to the configuration of a human being walking on a sloping surface. To this end, first, the kinematics and the dynamics of a bipedal robot walking down a ramp of shallow slope are investigated. Using the recursive Gibbs–Appell (G-A) methodology and Newton’s kinematic impact law, the governing dynamic equations of this bipedal robot in the two single-support and double-support phases are derived so that we can alter the system’s degrees of freedom without having to perform manual computations. Based on the dynamic equations obtained in the process, an eigenvalue problem is achieved, which can be solved to determine the suitable initial conditions needed for the passive gait of the bipedal robot. Then, having the initial and final conditions (before an impact with the inclined surface), a new method called “passive gait-based trajectory design (PGBTD)” is employed to determine the desired walking trajectory of the robot for one step. Considering the nonlinearity of the examined system, an optimal control method based on the state-dependent Riccati equation (SDRE) is employed to track the desired trajectory obtained. The performed simulations show that by just using a small amount of control energy at the beginning of each step, the steady and continuous gait of the bipedal robot on sloping surfaces can be controlled.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139500182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multibody Models Generated from Natural Language 从自然语言生成多体模型

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-01-17 DOI: 10.1007/s11044-023-09962-0

Johannes Gerstmayr, Peter Manzl, Michael Pieber

{"title":"Multibody Models Generated from Natural Language","authors":"Johannes Gerstmayr, Peter Manzl, Michael Pieber","doi":"10.1007/s11044-023-09962-0","DOIUrl":"https://doi.org/10.1007/s11044-023-09962-0","url":null,"abstract":"Computational models are conventionally created with input data, script files, programming interfaces, or graphical user interfaces. This paper explores the potential of expanding model generation, with a focus on multibody system dynamics. In particular, we investigate the ability of Large Language Model (LLM), to generate models from natural language. Our experimental findings indicate that LLM, some of them having been trained on our multibody code Exudyn, surpass the mere replication of existing code examples. The results demonstrate that LLM have a basic understanding of kinematics and dynamics, and that they can transfer this knowledge into a programming interface. Although our tests reveal that complex cases regularly result in programming or modeling errors, we found that LLM can successfully generate correct multibody simulation models from natural-language descriptions for simpler cases, often on the first attempt (zero-shot).After a basic introduction into the functionality of LLM, our Python code, and the test setups, we provide a summarized evaluation for a series of examples with increasing complexity. We start with a single mass oscillator, both in SciPy as well as in Exudyn, and include varied inputs and statistical analysis to highlight the robustness of our approach. Thereafter, systems with mass points, constraints, and rigid bodies are evaluated. In particular, we show that in-context learning can levitate basic knowledge of a multibody code into a zero-shot correct output.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"14 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139500412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison between EMG-based and optimisation-based approaches for back-muscle forces and intervertebral efforts 基于肌电图的方法与基于优化的方法在背部肌肉力量和椎间力度方面的比较

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-01-17 DOI: 10.1007/s11044-023-09963-z

Simon Hinnekens, Philippe Mahaudens, Christine Detrembleur, Paul Fisette

{"title":"Comparison between EMG-based and optimisation-based approaches for back-muscle forces and intervertebral efforts","authors":"Simon Hinnekens, Philippe Mahaudens, Christine Detrembleur, Paul Fisette","doi":"10.1007/s11044-023-09963-z","DOIUrl":"https://doi.org/10.1007/s11044-023-09963-z","url":null,"abstract":"In biomechanics, computing muscle forces and joint efforts with mathematical optimisation copes with the muscle-redundancy problem, i.e. an infinity of possible muscle forces for a unique configuration. Achievements have been made to develop cost functions that reflect physiologically more correct muscle strategies and to validate them with experiments. It has also been proposed to use experimental input such as electromyography (EMG) in the model to guide the optimisation computation. In line with that, the present study proposes an EMG-based approach to compute back-muscle forces and the resulting intervertebral efforts in a horizontal static configuration of the trunk. This approach is based on EMG signals of three back muscles, lumbar and thoracic paravertebral muscles and the quadratus lumborum (QL), recorded on 19 healthy male subjects. Results of this approach were compared with those from optimisation computations involving four cost functions, classically used in the literature for the trunk and the spine. Our approach showed that muscle forces and intervertebral efforts were in line with these computed by mathematical optimisation, but muscle forces obtained with our approach were more representative of the measured EMG signals compared to muscle forces computed by optimisation. Indeed, three of the four cost functions completely missed to recruit the QL, while the latter was clearly activated during the experiment. This result highlights that EMG and experimental input should be more considered when using a musculoskeletal model and optimisation tools. Since the EMG-based approach used in this study was based on a pure deterministic distribution of a global equivalent force, future work will focus on involving EMG input in the optimisation process to guide its solution in a more physiological manner.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"16 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139500230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling and system identification of uninhabited airship with a slung payload 带悬挂式有效载荷的无人驾驶飞艇的建模和系统识别

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2024-01-16 DOI: 10.1007/s11044-023-09961-1

Osama Obeid, Eric Lanteigne

引用次数: 0

Reliability evaluation of reinforcement learning methods for mechanical systems with increasing complexity 针对复杂性不断增加的机械系统的强化学习方法的可靠性评估

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2023-12-22 DOI: 10.1007/s11044-023-09960-2

Peter Manzl, Oleg Rogov, Johannes Gerstmayr, A. Mikkola, Grzegorz Orzechowski

引用次数: 0

Symbolic multibody models for digital-twin applications 数字双轴应用的符号多体模型

IF 3.4 2区工程技术

Multibody System Dynamics Pub Date : 2023-12-18 DOI: 10.1007/s11044-023-09957-x

Nicolas Docquier, Krzysztof Lipinski, Olivier Lantsoght, Sebastien Timmermans, Paul Fisette

{"title":"Symbolic multibody models for digital-twin applications","authors":"Nicolas Docquier, Krzysztof Lipinski, Olivier Lantsoght, Sebastien Timmermans, Paul Fisette","doi":"10.1007/s11044-023-09957-x","DOIUrl":"https://doi.org/10.1007/s11044-023-09957-x","url":null,"abstract":"Symbolic generation of multibody systems equations of motion appeared in the 1980s. In addition to their computational advantage over their numerical counterparts, symbolic models can be very easily and straightforwardly interfaced with a wide range of software environments and hardware devices. These two features place this approach in a pole position to participate and intervene in the design of digital twins for systems such as vehicles, manipulators, walking robots or haptic devices.In this context, the first goal of this paper is to highlight the interest of symbolically generated multibody models – at the root of the ROBOTRAN program – in the form of a standalone set of equations calculating the dynamic model of multibody systems, for use as a computational component within a Digital-Twin-type process. The next goal is to embed realistic and complex multibody models within processes or devices whose functioning requires a synchronized real-time computation – or analysis – of their motion.An implementation (i) on specific hardware and (ii) on two extremely opposite but revealing applications (namely a railway vehicle and a digital piano) are presented to highlight the usefulness of symbolic models for the development of current and future multibody-based digital twins.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"241 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138714485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0