We consider a new approach to digital human simulation, using Model Predictive Control (MPC). This approach permits a virtual human to react online to unanticipated disturbances that occur in the course of performing a task. In particular, we predict the motion of a virtual human in response to two different types of real world disturbances: impulsive and sustained. This stands in contrast to prior approaches where all such disturbances need to be known a priori and the optimal reactions must be computed off line. We validate this approach using a planar 3 degrees of freedom serial chain mechanism to imitate the human upper limb. The response of the virtual human upper limb to various inputs and external disturbances is determined by solving the Equations of Motion (EOM). The control input is determined by the MPC Controller using only the current and the desired states of the system. MPC replaces the closed loop optimization problem with an open loop optimization allowing the ease of implementation of control law. Results presented in this thesis show that the proposed controller can produce physically realistic adaptive simulations of a planar upper limb of digital human in presence of impulsive and sustained disturbances.

A new optimization algorithm, which can efficiently solve large-scale constrained non-linear optimization problems and leverage parallel computing, is designed and studied. The new algorithm, referred to herein as LASO or LArge Scale Optimizer, combines the best features of various algorithms to create a computationally efficient algorithm with strong convergence properties. Numerous algorithms were implemented and tested in its creation. Bound-constrained, step-size, and constrained algorithms have been designed that push the state-of-the-art. Along the way, five novel discoveries have been made: (1) a more efficient and robust method for obtaining second order Lagrange multiplier updates in Augmented Lagrangian algorithms, (2) a method for directly identifying the active constraint set at each iteration, (3) a simplified formulation of the penalty parameter sub-problem, (4) an efficient backtracking line-search procedure, (5) a novel hybrid line-search trust-region step-size calculation method. The broader impact of these contributions is that, for the first time, an Augmented Lagrangian algorithm is made to be competitive with state-of-the-art Sequential Quadratic Programming and Interior Point algorithms. The present work concludes by showing the applicability of the LASO algorithm to simulate one step of digital human walking and to accelerate the optimization process using parallel computing.

Made available in DSpace on 2016-06-02T19:51:40Z (GMT). No. of bitstreams: 1 2245.pdf: 5872409 bytes, checksum: b12b83b426b4420e3e1477afb63c08df (MD5) Previous issue date: 2009-02-09 / This research aims at presenting the human modeling and simulation contextualized by Ergonomic Work Analysis (EWA) and Probable Future Activities to assist in the design of new workstations. Two case studies in which human simulation was applied using the software Jack were analyzed. The first case study concerns the design of a new attendance counter in a Governmental Postal Company. The second concerns the design of a workstation in the production line of surgical needles in an industry of hygiene and medical products. The results indicate the contributions and challenges of using such technology in projects aiming envisaging issues of health and productivity. The use of simulation together with the Ergonomic Work Analysis (EWA) enabled predicting probable future activities and the participation and integration of actors involved in these social process. / Esta pesquisa apresenta como a ferramenta computacional de Modelagem e Simulação Humana contextualizada pela Análise Ergonômica do Trabalho (AET) e pela análise da Atividade Futura Provável pode auxiliar nos processos de projeto de postos de trabalho. São analisados dois estudos de caso nos quais a Simulação Humana foi empregada com auxílio do software Jack (UGS Siemens). O primeiro estudo aborda a concepção de um balcão de atendimento em uma empresa pública de serviços postais. O segundo apresenta o desenvolvimento de uma estação de trabalho de abastecimento de agulhas cirúrgicas em uma empresa de manufatura de produtos relacionados as áreas de saúde e higiene. A partir dos resultados dos estudos de caso são explicitadas as contribuições e desafios da utilização dessa tecnologia em projetos de concepção, visando equacionar as questões do bem-estar humano e da produtividade. O uso da simulação, integrada ao processo de intervenção da AET, permitiu melhorar a antecipação das futuras atividades prováveis das novas situações de trabalho e auxiliou a integração e comunicação dos atores envolvidos nesses processos sociais.