Applying DHMs in ergonomic design of vehicle interiors has been established for many years. Most use cases focus on various aspects of static driving configurations. But several dynamical occupant tasks must be evaluated for new vehicle concepts in addition. Because of the task complexity these tests are still performed in physical mock-ups. Over the past years new DHM technologies have supported evaluating dynamic ergonomics of interior designs in digital mock-ups more efficient. Nevertheless, there are still simulation aspects to be improved for proper industrial applications. This paper presents the recent development progress on knowledge-based motion simulation techniques using motion capture data and DHM prediction methods. The focus was put on a large variability of motions in the database, more user control on the simulated motions and functions for collision avoidance. Based on adjustable mock-ups, a range of ingress and egress motions into a truck and a passenger car were systematically measured taking various positions of vehicle components like steps, doors, pillars and roofs into account. These motion takes were reconstructed and annotated by DHMs and stored in a database. A new simulation tool was developed which use the database to predict motions in virtual environments. The GUI provides a range of motion components subjected to various motion data and simulation methods. These components can be combined to create a cumulative motion. In addition, the intersection frames of consecutive components can be controlled by user-defined postures or tasks. Smooth transitions are supported by specific truncating and sewing up consecutive motions. In addition, the tool got new functions to consider collision avoidance during simulation. First, characteristic parameters (door angle) are extracted from the environment and used to find corresponding collision-free motions in the database. Second, specific geometric constraints avoid collisions at key frames. Applying both functions supports qualitative motion strategy changes and quantitative body positions to cope with collision situations. The tool development is accompanied by user evaluations with respect to usability and prediction capabilities. These identified open issues to be solved and pushed the tool further forward to a productive level.
{"title":"On the progress of knowledge-based motion simulation techniques in ergonomic vehicle design","authors":"Hans-Joachim Wirsching, N. Hofmann","doi":"10.17077/dhm.31752","DOIUrl":"https://doi.org/10.17077/dhm.31752","url":null,"abstract":"Applying DHMs in ergonomic design of vehicle interiors has been established for many years. Most use cases focus on various aspects of static driving configurations. But several dynamical occupant tasks must be evaluated for new vehicle concepts in addition. Because of the task complexity these tests are still performed in physical mock-ups. Over the past years new DHM technologies have supported evaluating dynamic ergonomics of interior designs in digital mock-ups more efficient. Nevertheless, there are still simulation aspects to be improved for proper industrial applications. This paper presents the recent development progress on knowledge-based motion simulation techniques using motion capture data and DHM prediction methods. The focus was put on a large variability of motions in the database, more user control on the simulated motions and functions for collision avoidance. Based on adjustable mock-ups, a range of ingress and egress motions into a truck and a passenger car were systematically measured taking various positions of vehicle components like steps, doors, pillars and roofs into account. These motion takes were reconstructed and annotated by DHMs and stored in a database. A new simulation tool was developed which use the database to predict motions in virtual environments. The GUI provides a range of motion components subjected to various motion data and simulation methods. These components can be combined to create a cumulative motion. In addition, the intersection frames of consecutive components can be controlled by user-defined postures or tasks. Smooth transitions are supported by specific truncating and sewing up consecutive motions. In addition, the tool got new functions to consider collision avoidance during simulation. First, characteristic parameters (door angle) are extracted from the environment and used to find corresponding collision-free motions in the database. Second, specific geometric constraints avoid collisions at key frames. Applying both functions supports qualitative motion strategy changes and quantitative body positions to cope with collision situations. The tool development is accompanied by user evaluations with respect to usability and prediction capabilities. These identified open issues to be solved and pushed the tool further forward to a productive level.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122589630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work presents a model-based method of evaluating and quantifying stability characteristics of human walking in the sagittal plane. The stability criteria used for this analysis are boundaries in the state space of the center of mass (COM), which represent the maximum capability of a human to maintain balance in single support (SS) and double support (DS) phases or to make a desired step without falling. Complete models of the system dynamics, biomechanical characteristics, its contact interaction with the ground, and gait parameters, are considered. Experimental human COM trajectories during walking are analyzed against computed stability boundaries to quantify the nature of human gait across walking speeds. Stability comparisons with other robotic platforms, an exoskeleton and a humanoid robot, are also provided.
{"title":"Balance stability characteristics of human walking with preferred, fast, and slow speeds","authors":"Joo H. Kim, William Z. Peng","doi":"10.17077/dhm.31773","DOIUrl":"https://doi.org/10.17077/dhm.31773","url":null,"abstract":"This work presents a model-based method of evaluating and quantifying stability characteristics of human walking in the sagittal plane. The stability criteria used for this analysis are boundaries in the state space of the center of mass (COM), which represent the maximum capability of a human to maintain balance in single support (SS) and double support (DS) phases or to make a desired step without falling. Complete models of the system dynamics, biomechanical characteristics, its contact interaction with the ground, and gait parameters, are considered. Experimental human COM trajectories during walking are analyzed against computed stability boundaries to quantify the nature of human gait across walking speeds. Stability comparisons with other robotic platforms, an exoskeleton and a humanoid robot, are also provided.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131717915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenkai Zhao, L. Gao, Benjamin Simpson, Neil Mansfield, James Campbell
Repeated High-G shocks and whole-body vibration (WBV) can increase the risk of fatigue and injuries in the lumbar region of the spine for crew and passengers on High-speed craft (HSC). Existing reviews have suggested the beneficial effects of abdominal belts regarding lumbar torso stabilization and spinal unloading. The paper provides a novel 3-D seated human model with a virtual belt to simulate the belt effects for occupants on HSC. The model is built with AnyBody, a commercial software for musculoskeletal simulation based on the inverse dynamics method. The belt behaves like an additional force exerted in the lumbar region, and the force magnitude has been optimized to avoid discomfort during long journeys. The belt effects have been studied with different levels of wave shock, anthropometries, and belt design parameters such as belt width and position. Wave shocks exerted on seat surface are considered to include both vertical and off-vertical (horizontal) acceleration and expressed with a half-sine pulse. The belt effects are evaluated with intra-abdominal pressure (IAP), transversus muscle activities, and spinal compressive force. The results have shown a combined increase of IAP (137% maximum) and a decrease of spinal compressive force at the L4/L5 joint (15.5% maximum) once the belt is applied under various circumstances. Transverse abdominis activity is also reduced with belt application. The belt performs best when it covers the entire lumbar region. Reduction of belt width might lead to increased muscle activity for the muscle that
{"title":"Simulation of abdominal belt effects on IAP and spinal compressive force with musculoskeletal human model","authors":"Zhenkai Zhao, L. Gao, Benjamin Simpson, Neil Mansfield, James Campbell","doi":"10.17077/dhm.31762","DOIUrl":"https://doi.org/10.17077/dhm.31762","url":null,"abstract":"Repeated High-G shocks and whole-body vibration (WBV) can increase the risk of fatigue and injuries in the lumbar region of the spine for crew and passengers on High-speed craft (HSC). Existing reviews have suggested the beneficial effects of abdominal belts regarding lumbar torso stabilization and spinal unloading. The paper provides a novel 3-D seated human model with a virtual belt to simulate the belt effects for occupants on HSC. The model is built with AnyBody, a commercial software for musculoskeletal simulation based on the inverse dynamics method. The belt behaves like an additional force exerted in the lumbar region, and the force magnitude has been optimized to avoid discomfort during long journeys. The belt effects have been studied with different levels of wave shock, anthropometries, and belt design parameters such as belt width and position. Wave shocks exerted on seat surface are considered to include both vertical and off-vertical (horizontal) acceleration and expressed with a half-sine pulse. The belt effects are evaluated with intra-abdominal pressure (IAP), transversus muscle activities, and spinal compressive force. The results have shown a combined increase of IAP (137% maximum) and a decrease of spinal compressive force at the L4/L5 joint (15.5% maximum) once the belt is applied under various circumstances. Transverse abdominis activity is also reduced with belt application. The belt performs best when it covers the entire lumbar region. Reduction of belt width might lead to increased muscle activity for the muscle that","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129992339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Exoskeletons are remarkable technologies that improve human strength, reduce fatigue, and restore users' abilities. In this study, a novel physics-based optimization formulation is proposed to find the optimal control of a powered elbow exoskeleton to aid the human-robot collaborative lifting task. The threedimensional (3D) human arm model has 13 degrees of freedom (DOFs), and the 3D robot arm (Sawyer robot arm) model has 10 DOFs. The inverse dynamics optimization is utilized to find the optimal lifting motion and the optimal exoskeleton assistive torque. The 3D human arm and robot arm are modeled in Denavit-Hartenberg (DH) representation. The electromechanical dynamics of the DC motor of the exoskeleton are considered in the dynamic human-robot collaborative lifting optimization. In addition, the 3D box is modeled as a floating-base rigid body with 6 global DOFs. The human-box and robot-box interactions are characterized as a collection of grasping forces. The joint torque squares of human arm and robot arm are minimized subjected to physicsand task-based constraints. The design variables include (1) control points of cubic B-splines of joint angle profiles of the human arm, robotic arm, and box; (2) control points of cubic B-splines of motor current for the exoskeleton; and (3) the discretized grasping forces during lifting. The constraints include joint angle limits for human arm and robot arm, joint torque limits for human arm, robot arm and exoskeleton, human-robot grasping positions, box balance condition, initial and final box locations, and bounds on design variables. A numerical example of lifting a 10 kg box is simulated. The nonlinear collaborative lifting optimization problem is solved using a sequential quadratic programming (SQP) method in SNOPT, and the optimal solutions are found in 136.11 seconds. The simulation reports the grasping force profiles, human arm’s joint angles, and the powered elbow exoskeleton’s torque profiles. The results reveal that the proposed optimization formulation can find the exoskeleton's optimal control and lifting strategy for the human-robot collaborative lifting task.
{"title":"Modeling and simulation of a powered exoskeleton system to aid human-robot collaborative lifting","authors":"Asif Arefeen, Y. Xiang","doi":"10.17077/dhm.31768","DOIUrl":"https://doi.org/10.17077/dhm.31768","url":null,"abstract":"Exoskeletons are remarkable technologies that improve human strength, reduce fatigue, and restore users' abilities. In this study, a novel physics-based optimization formulation is proposed to find the optimal control of a powered elbow exoskeleton to aid the human-robot collaborative lifting task. The threedimensional (3D) human arm model has 13 degrees of freedom (DOFs), and the 3D robot arm (Sawyer robot arm) model has 10 DOFs. The inverse dynamics optimization is utilized to find the optimal lifting motion and the optimal exoskeleton assistive torque. The 3D human arm and robot arm are modeled in Denavit-Hartenberg (DH) representation. The electromechanical dynamics of the DC motor of the exoskeleton are considered in the dynamic human-robot collaborative lifting optimization. In addition, the 3D box is modeled as a floating-base rigid body with 6 global DOFs. The human-box and robot-box interactions are characterized as a collection of grasping forces. The joint torque squares of human arm and robot arm are minimized subjected to physicsand task-based constraints. The design variables include (1) control points of cubic B-splines of joint angle profiles of the human arm, robotic arm, and box; (2) control points of cubic B-splines of motor current for the exoskeleton; and (3) the discretized grasping forces during lifting. The constraints include joint angle limits for human arm and robot arm, joint torque limits for human arm, robot arm and exoskeleton, human-robot grasping positions, box balance condition, initial and final box locations, and bounds on design variables. A numerical example of lifting a 10 kg box is simulated. The nonlinear collaborative lifting optimization problem is solved using a sequential quadratic programming (SQP) method in SNOPT, and the optimal solutions are found in 136.11 seconds. The simulation reports the grasping force profiles, human arm’s joint angles, and the powered elbow exoskeleton’s torque profiles. The results reveal that the proposed optimization formulation can find the exoskeleton's optimal control and lifting strategy for the human-robot collaborative lifting task.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133674962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The design of any functional clothing requires elastic human body models. The detailed FEM models as for instance THUMS (Total Human Model for Safety) (Toyota THUMS Webpage) for car crash simulations are unnecessary accurate, computational intensive and not practicable for clothing and other product development processes. For correct simulation of the mechanical interaction a full-scale FEM Models of the humans with enough suitable accuracy and complexity, but at efficient computation and often in specific poses are required. This works presents the development steps and current state of an algorithm for automatic solid FEM mesh generator for human bodies, based on high speed 3D (4D) scan data.
任何功能性服装的设计都需要有弹性的人体模型。详细的有限元模型，例如用于汽车碰撞模拟的THUMS (Total Human Model for Safety)(丰田THUMS网页)是不必要的精确，计算量大，不适用于服装和其他产品开发过程。为了正确地模拟人体的力学相互作用，必须建立具有适当精度和复杂度的人体全尺寸有限元模型，但通常需要在特定的位姿下进行高效的计算。本文介绍了一种基于高速三维(4D)扫描数据的人体实体有限元网格自动生成算法的发展步骤和现状。
{"title":"Automatic generation of partially homogenized FEM human body models based on 3D body scan data","authors":"Y. Kyosev, T. Kühn, Ann-Malin Schmidt","doi":"10.17077/dhm.31779","DOIUrl":"https://doi.org/10.17077/dhm.31779","url":null,"abstract":"The design of any functional clothing requires elastic human body models. The detailed FEM models as for instance THUMS (Total Human Model for Safety) (Toyota THUMS Webpage) for car crash simulations are unnecessary accurate, computational intensive and not practicable for clothing and other product development processes. For correct simulation of the mechanical interaction a full-scale FEM Models of the humans with enough suitable accuracy and complexity, but at efficient computation and often in specific poses are required. This works presents the development steps and current state of an algorithm for automatic solid FEM mesh generator for human bodies, based on high speed 3D (4D) scan data.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129824544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A digital human modelling (DHM) software is a valuable tool in virtual manufacturing since it supports proactive consideration of ergonomics when designing new workstations by facilitating simulation of manual assembly work and by providing ergonomic assessments of different design proposals. Despite the advantage, there are still a lot of assembly tasks that are not simulated and assessed proactively. One reason is that it is time consuming for the user, even for simple tasks, to create and set up the assembly simulations. Increasing the automation level of DHM software has the potential to both increase the number of assembly task simulated as well as enabling ergonomics to proactively be included in other manufacturing and product design related decisions. However, an increased automation level requires a manikin that automatically can compute collision free and ergonomically sound motions based on some sort of instruction language that supports the DHM software user to communicate to the manikin of what tasks the manikin is to perform. The instructions are, during simulation, interpreted by a simulation framework as path planning instances for the manikin, which results in motions that accomplishes the tasks. In this work, we explore the possibility to use the DHM software IMMA’s instruction language to further increase the automation level and to identify gaps between the current functionality and the functional requirements for a more automated simulation framework. More specifically, we investigate the requirements for simulations where: 1) when two the forces handle assembly station; and 3) Manikins interact with moving objects, e.g. during assembly of a part on a moving assembly line, or grasping a part that is moved by a collaborative robot.
{"title":"Identifying benefits of using an instruction language for virtual simulation of manual assembly and logistics","authors":"Peter Mårdberg, J. Carlson, D. Högberg","doi":"10.17077/dhm.31785","DOIUrl":"https://doi.org/10.17077/dhm.31785","url":null,"abstract":"A digital human modelling (DHM) software is a valuable tool in virtual manufacturing since it supports proactive consideration of ergonomics when designing new workstations by facilitating simulation of manual assembly work and by providing ergonomic assessments of different design proposals. Despite the advantage, there are still a lot of assembly tasks that are not simulated and assessed proactively. One reason is that it is time consuming for the user, even for simple tasks, to create and set up the assembly simulations. Increasing the automation level of DHM software has the potential to both increase the number of assembly task simulated as well as enabling ergonomics to proactively be included in other manufacturing and product design related decisions. However, an increased automation level requires a manikin that automatically can compute collision free and ergonomically sound motions based on some sort of instruction language that supports the DHM software user to communicate to the manikin of what tasks the manikin is to perform. The instructions are, during simulation, interpreted by a simulation framework as path planning instances for the manikin, which results in motions that accomplishes the tasks. In this work, we explore the possibility to use the DHM software IMMA’s instruction language to further increase the automation level and to identify gaps between the current functionality and the functional requirements for a more automated simulation framework. More specifically, we investigate the requirements for simulations where: 1) when two the forces handle assembly station; and 3) Manikins interact with moving objects, e.g. during assembly of a part on a moving assembly line, or grasping a part that is moved by a collaborative robot.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117017094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Often new digital tools are introduced alongside existing tools and workflows to augment and fill gaps in current processes. Virtual and augmented reality (XR) tools are currently being deployed in this way within design processes, allowing for interactive visualization in virtual environments including the use of DHM tools. Currently, the focus is on how to implement XR as a stand-alone tool for single user scenarios. However, in collaborative design contexts, screen-based and XR tools can be used together to leverage the benefits of each technology maximizing the potential of multi-user design processes. XR allows for an immersive exploration of designed objects in 3D space, while screen-based tools allow for easier notetaking and integration of additional non-3D software and meeting tools. Ensuring that these technologies are integrated in a mutually beneficial manner requires a framework for determining the best combination of technologies and interfaces for diverse design teams. This paper presents a framework for performing collaborative design reviews in a digital environment that can be accessed using both XR and 2D screen devices simultaneously. It enables asymmetric collaboration to provide each design team member with the technology that best fits their workflow and requirements.
{"title":"Improving the efficiency of virtual-reality-based ergonomics assessments with digital human models in multi-agent collaborative virtual environments","authors":"M. Waddell, Francisco García Rivera, M. Lamb","doi":"10.17077/dhm.31781","DOIUrl":"https://doi.org/10.17077/dhm.31781","url":null,"abstract":"Often new digital tools are introduced alongside existing tools and workflows to augment and fill gaps in current processes. Virtual and augmented reality (XR) tools are currently being deployed in this way within design processes, allowing for interactive visualization in virtual environments including the use of DHM tools. Currently, the focus is on how to implement XR as a stand-alone tool for single user scenarios. However, in collaborative design contexts, screen-based and XR tools can be used together to leverage the benefits of each technology maximizing the potential of multi-user design processes. XR allows for an immersive exploration of designed objects in 3D space, while screen-based tools allow for easier notetaking and integration of additional non-3D software and meeting tools. Ensuring that these technologies are integrated in a mutually beneficial manner requires a framework for determining the best combination of technologies and interfaces for diverse design teams. This paper presents a framework for performing collaborative design reviews in a digital environment that can be accessed using both XR and 2D screen devices simultaneously. It enables asymmetric collaboration to provide each design team member with the technology that best fits their workflow and requirements.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130914283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Goutham Sridhar, Léo Savonnet, Y. Lafon, Xuguang Wang
Finite Element Models (FEM) of the human body (HBM) are used to analyze static seating discomfort mainly in terms of interface pressure distribution on the seat surface (Savonnet et al. 2018). However, most of the HBMs are not validated under actual seating conditions due to the difficulty in measuring internal body loads such as soft tissue deformation, intervertebral disc pressures, etc. The rare HBM related studies claiming validation have only analyzed the interface pressure distribution. Recent experiments conducted with and without foam for different seat pan inclinations (Fig 1b) using Open MRI indicate that soft tissue deformation below the Ischial Tuberosity (IT) is affected by both contact pressure and shear and thus could be an objective indicator in seat discomfort assessment (Wang et al. 2021). The aim of this present study is to report a preliminary evaluation of FE-HBMs against these subject-specific experimental data in terms of interface pressure and soft tissue deformation.
人体有限元模型(FEM)主要从座椅表面的界面压力分布来分析静态座椅不适(Savonnet et al. 2018)。然而，由于难以测量人体内部载荷(如软组织变形、椎间盘压力等)，大多数HBMs并未在实际坐位条件下进行验证。很少有声称验证的HBM相关研究只分析了界面压力分布。最近使用Open MRI对不同坐垫倾斜度进行的有泡沫和无泡沫实验(图1b)表明，坐骨结节(坐骨结节)下方的软组织变形受到接触压力和剪切的影响，因此可以作为评估坐位不适的客观指标(Wang et al. 2021)。本研究的目的是报告FE-HBMs在界面压力和软组织变形方面的初步评估。
{"title":"Evaluation of personalized human body buttock-thigh finite element models in terms of soft tissue deformation for seat comfort assessment","authors":"Goutham Sridhar, Léo Savonnet, Y. Lafon, Xuguang Wang","doi":"10.17077/dhm.31774","DOIUrl":"https://doi.org/10.17077/dhm.31774","url":null,"abstract":"Finite Element Models (FEM) of the human body (HBM) are used to analyze static seating discomfort mainly in terms of interface pressure distribution on the seat surface (Savonnet et al. 2018). However, most of the HBMs are not validated under actual seating conditions due to the difficulty in measuring internal body loads such as soft tissue deformation, intervertebral disc pressures, etc. The rare HBM related studies claiming validation have only analyzed the interface pressure distribution. Recent experiments conducted with and without foam for different seat pan inclinations (Fig 1b) using Open MRI indicate that soft tissue deformation below the Ischial Tuberosity (IT) is affected by both contact pressure and shear and thus could be an objective indicator in seat discomfort assessment (Wang et al. 2021). The aim of this present study is to report a preliminary evaluation of FE-HBMs against these subject-specific experimental data in terms of interface pressure and soft tissue deformation.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124626597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This short paper presents a novel approach to digitize scalp shape with a combination of a scalp probing rig and 3D head scanning.
本文介绍了一种结合头皮探测装置和三维头部扫描的数字化头皮形状的新方法。
{"title":"Digitizing human scalp shape through 3D scanning","authors":"Peng Li, Asbed Tashjian, M. Hurley","doi":"10.17077/dhm.31760","DOIUrl":"https://doi.org/10.17077/dhm.31760","url":null,"abstract":"This short paper presents a novel approach to digitize scalp shape with a combination of a scalp probing rig and 3D head scanning.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"59 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120872674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
DHM tools have been widely used to analyze and improve vehicle occupant packaging and interior design in the automotive industry. However, these tools still present some limitations for this application. Accurately characterizing seated posture is crucial for ergonomic and safety evaluations. Current human posture and motion predictions in DHM tools are not accurate enough for the precise nature of vehicle interior design, typically requiring manual adjustments from DHM users to get more accurate driving and passenger simulations. Manual adjustment processes can be time-consuming, tedious, and subjective, easily causing non-repeatable simulation results. These limitations create the need to validate the simulation results with real-world studies, which increases the cost and time in the vehicle development process. Working with multiple Swedish automotive companies, we have begun to identify and specify the limitations of DHM tools relating to driver and passenger posture predictions given predefined vehicle geometry points/coordinates and specific human body parts relationships. Two general issues frame the core limitations. First, human kinematic models used in DHM tools are based on biomechanics models that do not provide definitions of these models in relation to vehicle geometries. Second, vehicle designers follow standards and regulations to obtain key human reference points in seated occupant locations. However, these reference points can fail to capture the range of human variability. This paper describes the relationship between a seated reference point and a biomechanical hip joint for driving simulations. The lack of standardized connection between occupant packaging guidelines and the biomechanical knowledge of humans creates a limitation for ergonomics designers and DHM users. We assess previous studies addressing hip joint estimation from different fields to establish the key aspects that might affect the relationship between standard vehicle geometry points and the hip joint. Then we suggest a procedure for standardizing points in human models within DHM tools. A better understanding of this problem may contribute to achieving closer to reality driving posture simulations and facilitating communication of ergonomics requirements to the design team within the product development process.
{"title":"Simulation of hip joint location for occupant packaging design","authors":"E. Perez Luque, E. Brolin, M. Lamb, D. Högberg","doi":"10.17077/dhm.31742","DOIUrl":"https://doi.org/10.17077/dhm.31742","url":null,"abstract":"DHM tools have been widely used to analyze and improve vehicle occupant packaging and interior design in the automotive industry. However, these tools still present some limitations for this application. Accurately characterizing seated posture is crucial for ergonomic and safety evaluations. Current human posture and motion predictions in DHM tools are not accurate enough for the precise nature of vehicle interior design, typically requiring manual adjustments from DHM users to get more accurate driving and passenger simulations. Manual adjustment processes can be time-consuming, tedious, and subjective, easily causing non-repeatable simulation results. These limitations create the need to validate the simulation results with real-world studies, which increases the cost and time in the vehicle development process. Working with multiple Swedish automotive companies, we have begun to identify and specify the limitations of DHM tools relating to driver and passenger posture predictions given predefined vehicle geometry points/coordinates and specific human body parts relationships. Two general issues frame the core limitations. First, human kinematic models used in DHM tools are based on biomechanics models that do not provide definitions of these models in relation to vehicle geometries. Second, vehicle designers follow standards and regulations to obtain key human reference points in seated occupant locations. However, these reference points can fail to capture the range of human variability. This paper describes the relationship between a seated reference point and a biomechanical hip joint for driving simulations. The lack of standardized connection between occupant packaging guidelines and the biomechanical knowledge of humans creates a limitation for ergonomics designers and DHM users. We assess previous studies addressing hip joint estimation from different fields to establish the key aspects that might affect the relationship between standard vehicle geometry points and the hip joint. Then we suggest a procedure for standardizing points in human models within DHM tools. A better understanding of this problem may contribute to achieving closer to reality driving posture simulations and facilitating communication of ergonomics requirements to the design team within the product development process.","PeriodicalId":111717,"journal":{"name":"Proceedings of the 7th International Digital Human Modeling Symposium (DHM 2022) and Iowa Virtual Human Summit 2022 -","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122367534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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