scholarly journals A CONCEPTUAL DESIGN FOR RECONFIGURABLE ROBOTS

2011 ◽  
Author(s):  
Farhad Aghili
Keyword(s):  
Conceptual Design ◽  
Mechanical Design ◽  
Twist Angle ◽  
Kinematic Chain ◽  
Control Synthesis ◽  
Kinematics Analysis ◽  
New Paradigm ◽  
Passive Joint ◽  
Reconfigurable Robots

The paper presents a new paradigm and conceptual design for reconfigurable robots. Unlike conventional reconfigurable robots, our design doesn't achieve reconfigurability by utilizing modular joints. But the robot is equipped with passive joints, i.e. joints with no actuator or sensor, which permit changing the Denavit-Hartenberg (DV) parameters such as the arm length, and the twist angle. The passive joints are controllable when the robot forms a closed kinematic chain. Also each passive joint is equipped with a built-in brake mechanism which is normally locked but it can be released whenever changing of the parameters is required. Kinematics analysis of such a robot plus control synthesis and mechanical design of the brake mechanism are described.

Design of a Human Knee Reeducation Mechanism

2019 ◽  
Vol 11 (1) ◽  
pp. 42-53
Author(s):  
Allaoua Brahmia ◽  
Ridha Kelaiaia
Keyword(s):  
Lower Limb ◽  
Mechanical Design ◽  
Kinematic Chain ◽  
Lower Limbs ◽  
Kinematic Structure ◽  
Robotic Device ◽  
Human Knee ◽  
Kinematic Study ◽  
Rehabilitation Exercise ◽  
New Machine

Abstract To establish an exercise in open muscular chain rehabilitation (OMC), it is necessary to choose the type of kinematic chain of the mechanical / biomechanical system that constitutes the lower limbs in interaction with the robotic device. Indeed, it’s accepted in biomechanics that a rehabilitation exercise in OMC of the lower limb is performed with a fixed hip and a free foot. Based on these findings, a kinematic structure of a new machine, named Reeduc-Knee, is proposed, and a mechanical design is carried out. The contribution of this work is not limited to the mechanical design of the Reeduc-Knee system. Indeed, to define the minimum parameterizing defining the configuration of the device relative to an absolute reference, a geometric and kinematic study is presented.

Selecting Kinematic Structures of Parallel Manipulators Using Symmetry and Connectivity

2015 ◽  
Author(s):  
Roberto Simoni ◽  
Henrique Simas ◽  
Daniel Martins
Keyword(s):  
Conceptual Design ◽  
Kinematic Chain ◽  
Parallel Manipulators ◽  
Connectivity Matrix ◽  
Early Stages

This paper presents an application of symmetry and connectivity to select kinematic structures of parallel manipulators. One kinematic chain can originate several mechanisms and each mechanism can originate several parallel manipulators and, in early stages of conceptual design, it is difficult to decide what is the most promising one. Hunt [1] introduced the concept of connectivity and, since then, the connectivity has been used as an important parameter to select the most appropriated parallel manipulators to develop determined task. However, it is difficult to analyze non isomorphic parallel manipulators from the connectivity matrix. In this sense, in this paper, we apply symmetry to reduce the set of parallel manipulators to a manageable few with the desired connectivity. As a result, all promising parallel manipulators originating from a kinematic chain can be analyzed without isomorphisms.

A model of the mechanical design process based on empirical data

1988 ◽  
Vol 2 (1) ◽  
pp. 33-52 ◽  
Author(s):  
David G. Ullman ◽  
Thomas G. Dietterich ◽  
Larry A. Stauffer
Keyword(s):  
Problem Solving ◽  
Detailed Analysis ◽  
Conceptual Design ◽  
Design Process ◽  
Empirical Data ◽  
Mechanical Design ◽  
Level Of Detail ◽  
Cad Tools ◽  
Design Alternatives ◽  
Key Features

This paper describes the task/episode accumulation model (TEA model) of non-routine mechanical design, which was developed after detailed analysis of the audio and video protocols of five mechanical designers. The model is able to explain the behavior of designers at a much finer level of detail than previous models. The key features of the model are (a) the design is constructed by incrementally refining and patching an initial conceptual design, (b) design alternatives are not considered outside the boundaries of design episodes (which are short stretches of problem solving aimed at specific goals), (c) the design process is controlled locally, primarily at the level of individual episodes. Among the implications of the model are the following: (a) CAD tools should be extended to represent the state of the design at more abstract levels, (b) CAD tools should help the designer manage constraints, and (c) CAD tools should be designed to give cognitive support to the designer.

A Computational Product Model for Conceptual Design Using SysML

2009 ◽  
Author(s):  
Stefan Wo¨lkl ◽  
Kristina Shea
Keyword(s):  
Product Development ◽  
Conceptual Design ◽  
Mechanical Design ◽  
System Development ◽  
Concept Design ◽  
Product Modeling ◽  
Product Model ◽  
Mechatronic Systems ◽  
Starting Point

The importance of the concept development phase in product development is contradictory to the level and amount of current computer-based support for it, especially with regards to mechanical design. Paper-based methods for conceptual design offer a far greater level of maturity and familiarity than current computational methods. Engineers usually work with software designed to address only a single stage of the concept design phase, such as requirements management tools. Integration with software covering other stages, e.g. functional modeling, is generally poor. Using the requirements for concept models outlined in the VDI 2221 guideline for systematic product development as a starting point, the authors propose an integrated product model constructed using the Systems Modeling Language (SysML) that moves beyond geometry to integrate all necessary aspects for conceptual design. These include requirements, functions and function structures, working principles and their structures as well as physical effects. In order to explore the applicability of SysML for mechanical design, a case study on the design of a passenger car’s luggage compartment cover is presented. The case study shows that many different SysML diagram types are suitable for formal modeling in mechanical concept design, though they were originally defined for software and control system development. It is then proposed that the creation and use of libraries defining generic as well as more complicated templates raises efficiency in modeling. The use of diagrams and their semantics for conceptual modeling make SysML a strong candidate for integrated product modeling of mechanical as well as mechatronic systems.

Function and Mechanism Formalization in Task Based Conceptual Design Method

2012 ◽  
Author(s):  
H. V. Darbinyan
Keyword(s):  
Conceptual Design ◽  
Mechanical Design ◽  
Design Method ◽  
General Concept ◽  
Design Tool ◽  
Concept Design ◽  
Scope Of Application ◽  
Core Idea ◽  
And Function ◽  
Mechanical Objects

Mechanism and function formalization problem is touched in a novel task based conceptual mechanical design method. The general concept and a specific application of this method were reported in earlier publications. Direct dependence between the function and mechanism, identical synthesis tools for various stages of design and for various mechanical objects are the features making the suggested method advantageously different from existing concept design approaches. The core idea of suggested conceptual design method is the direct relation between challenged function and the mechanical entity which is in charge of implementing the requested function. The existing task based conceptual design methods are not satisfying the designer’s needs for scope of application, universality of design means, visualization and formalization of both mechanical and functional fields. Formalization of functions and mechanisms is an important design tool that will facilitate synthesis, analyzes, visualization and archiving (data base creating) processes of mechanical development. Further progress in unveiling the resources of the suggested design method is mostly based on development of formalization means for both categories of functions and mechanisms. The current study is unveiling newly developed function and mechanism description language that is helping to formalize both mechanical and functional categories facilitating their involvement in design process and making the description of a new product’s mechanical development easy and understandable. Function formalization in conjunction with mechanism formalization allows to formulate precisely the design task and concentrate the designer’s attention on solution of a single task strictly arranged in the hierarchical function tree of all involved tasks and functions.

scholarly journals Task based conceptual design of a testing machine

2019 ◽  
Vol 287 ◽  
pp. 01008
Author(s):  
Hrayr Darbinyan
Keyword(s):  
Conceptual Design ◽  
Power Transmission ◽  
Mechanical Design ◽  
Design Method ◽  
Testing Machine ◽  
General Concept ◽  
Test Machine ◽  
Concept Design ◽  
Original Design ◽  
Design Cycle

A novel approach of task based conceptual design(TBCD) has been successfully used as direct guider and efficient developer of unique mechanical structures for many cases of mechanical design. Nearly a decade long efforts of elaboration of efficient every day usage formats for this method have been ended in convenient design pages suitable and applicable for revealing, describing, visualizing and managing the data necessary for organizing the design process from task definition to solutions satisfying original design tasks. The aim of current study is to show steps of a solution generation within frames of a single design cycle and extend this action over consecutive design cycles. Those steps are described from standpoint of general concept design method starting from key model and finished with final aggregation matrice as ultimate step of a single design cycle. Unified mathematical expressions are used for introduction and description of all worked out and developed components of conceptual design. The paper is arranged in a way to show gradual steps of conceptual design(CD) of a power transmission system – a pipe wrench life test machine.

scholarly journals Robust and fault tolerant control of modular and reconfigurable robots

2021 ◽  
Author(s):  
Sajan Abdul
Keyword(s):  
Dynamic Model ◽  
Distributed Control ◽  
Fault Tolerant ◽  
Joint Torque ◽  
Control Technique ◽  
Control Synthesis ◽  
Joint Control ◽  
Model Uncertainties ◽  
Reconfigurable Robots ◽  
Reconfigurable Robot

Modular and reconfigurable robot has been one of the main areas of robotics research in recent years due to its wide range of applications, especially in aerospace sector. Dynamic control of manipulators can be performed using joint torque sensing with little information of the link dynamics. From the modular robot perspective, this advantage offered by the torque sensor can be taken to enhance the modularity of the control system. Known modular robots though boast novel and diverse mechanical design on joint modules in one way or another, they still require the whole robot dynamic model for motion control, and modularity offered in the mechanical side does not offer any advantage in the control design. In this work, a modular distributed control technique is formulated for modular and reconfigurable robots that can instantly adapt to robot reconfigurations. Under this control methodology, a modular and reconfigurable robot is stabilized joint by joint, and modules can be added or removed without the need of re-tuning the controller. Model uncertainties associated with load and links are compensated by the use of joint torque sensors. Other model uncertainties at each joint module are compensated by a decomposition based robust controller for each module. The proposed distributed control technique offers a ‘modular’ approach, featuring a unique joint-by-joint control synthesis of the joint modules. Fault tolerance and fault detection are formulated as a decentralized control problem for modular and reconfigurable robots in this thesis work. The modularity of the system is exploited to derive a strategy dependent only on a single joint module, while eliminating the need for the motion states of other joint modules. While the traditional fault tolerant and detection schemes are suitable for robots with the whole dynamic model, this proposed technique is ideal for modular and reconfigurable robots because of its modular nature. The proposed methods have been investigated with simulations and experimentally tested using a 3-DOF modular and reconfigurable robot.

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