Motion/Posture Modeling and Simulation Verification of Physically Handicapped in Manufacturing System Design

Non-obstacle design is critical to tailor physically handicapped workers in manufacturing system. Simultaneous consideration of variability in physically disabled users, machines and environment of the manufacturing system is extremely complex and generally requires modeling of physically handicapped interaction with the system. Most current modeling either concentrates on the task results or functional disability. The integration of physical constraints with task constraints is far more complex because of functional disability and its extended influence on adjacent body parts. A framework is proposed to integrate the two constraints and thus model the specific behavior of the physical handicapped in virtual environment generated by product specifications. Within the framework a simplified model of physical disabled body is constructed, and body motion is generated based on 3 levels of constraints（effecter constraints, kinematics constraints and physical constraints）. The kinematics and dynamic calculations are made and optimized based on the weighting manipulated by the kinematics constraints and dynamic constraints. With object transferring task as example, the model is validated in Jack 6.0. Modelled task motion elements except for squatting and overreaching well matched with captured motion elements. The proposed modeling method can model the complex behavior of the physically handicapped by integrating both task and physical disability constraints.

Applications and research trends of digital human models in the manufacturing industry

Virtual reality(VR)has been widely used in various manufacturing industries,and VR-based virtual manufacturing has received significant attention in the current intelligent manufacturing era.Digital human models(DHMs)are essential for virtual manufacturing applications.Additionally,researching new applications of DHMs has developed into an important academic research field.This paper aims to identify the applications and research trends of DHMs in the manufacturing industry and to provide a reference for the continued development of virtual manufacturing and DHMs.We selected a total of 49 related articles from a large number of articles published between 2014 and 2019.The applications of DHMs in the manufacturing industry are analyzed from different perspectives and various relevant technical limitations are discussed.The results indicate that the applications of DHMs differ significantly between different types of fields.The automotive industry is the main application field for DHMs,and assembly/maintenance simulations and evaluations are the main application types.Additionally,there are still some limitations in the establishment of virtual environments,motion control,and DHM evaluation that should be addressed.Finally,research trends in the application of DHMs are illustrated and discussed,including the planning and assessment of human-robot collaboration systems,the combination of DHMs and augmented reality,and improved motion planning for DHMs.In summary,the application of DHMs can improve the realism and effectiveness of virtual manufacturing,and DHMs will be more widely and deeply studied and applied in various manufacturing industries in the near future.