Advanced Strategies for Robot Manipulators

Amongst the robotic systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. Modern manipulators are designed complicatedly and need to do more precise, crucial and critical tasks. So, the simple traditional control methods cannot be efficient, and advanced control strategies with considering special constraints are needed to establish. In spite of the fact that groundbreaking researches have been carried out in this realm until now, there are still many novel aspects which have to be explored

Systems Statistical Engineering – Systems Hierarchical Constraint Propagation

Cotter (ASEM-IAC 2012, 2015, 2016, 2017): (1) identified the gaps in knowledge that statistical engineering needed to address and set forth a working definition of and body of knowledge for statistical engineering; (2) proposed a systemic causal Bayesian hierarchical model that addressed the knowledge gap needed to integrate deterministic mathematical engineering causal models within a stochastic framework; (3) specified the modeling methodology through which statistical engineering models could be developed, diagnosed, and applied to predict systemic mission performance; and (4) proposed revisions to and integration of IDEF0 as the framework for developing hierarchical qualitative systems models. In the last work, Cotter (2017) noted that a necessary dimension of the systems statistical engineering body of knowledge is hierarchical constraint propagation to assure that imposed environmental economic, legal, political, social, and technical constraints are consistently decomposed to subsystems , modules, and components and that modules, and subsystems socio-technical constraints are mapped to systemic mission performance. This paper presents systems theory, constraint propagation theory, and Bayesian constrained regression theory relevant to the problem of systemic hierarchical constraint propagation and sets forth the theoretical basis for their integration into the systems statistical engineering body of knowledge

Synthesis of Products, Processes and Control for Dimensional Quality in Reconfigurable Assembly Systems.

Reconfigurable systems and tools have given manufacturers the possibility to quickly adapt to changes in the market place. Such systems allow the production of different products with simple and quick reconfiguration. Another advantage of reconfigurable systems is that the accuracy of the tools provides a unique opportunity to compensate errors and deviations as they occur along the manufacturing system, hence improving product quality. This dissertation deals with the design of products, processes and controllers to enhance dimensional quality of products produced in reconfigurable assembly processes. The successful synthesis of these topics will lead to new levels of quality and responsiveness. Fundamental research has been conducted in dimensional control of reconfigurable multistation assembly systems. This includes three topics related to the design of products, processes, and controls. These are: o Development of feedforward controllers: Feedforward controllers allow deviation compensation on a part-by-part basis using reconfigurable tools. The control actions are obtained through the combination of multistation assembly models, in-line measurements (used to measure deviations along the process), and the characteristics and requirements of products/processes, in an optimization framework. Simulation results show that the proposed control approach is effective on reducing variation. o Optimal selection and distribution of actuators in multistation assembly processes: The availability of reconfigurable tools in the process enables error correction; however, it is too expensive to install at every location. The selection and distribution of the actuators is focused on cost effectively reducing variation in multistation assembly processes. Simulations results prove that dimensional variation could be significantly reduced through an appropriate distribution of actuators. o Robust fixture design for a product family assembled in a reconfigurable multistation line: The assembly of a product family in a reconfigurable line demands fixtures sharing across products. The sharing impacts the products robustness to fixture variation due to frequent systems reconfiguration and tradeoffs made in the design of fixtures to accommodate the family in the single system. A robust fixture layout for a product family is achieved by reducing the combined sensitivity of the whole family to fixture variation and considering product and process constraints.Ph.D.Mechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/57657/2/leiv_1.pd