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Optimal task-space manipulability of hybrid 4-DOF dual-arm cam-lock manipulators
, Article Proceeding of the 5th International Symposium on Mechatronics and its Applications, ISMA 2008, 27 May 2008 through 29 May 2008, Amman ; 2008 ; 9781424420346 (ISBN) ; Meghdari, A ; Sohrabpour, S ; Sharif University of Technology
2008
Abstract
The Dual-Arm Cam-Lock robot is a reconfigurable manipulator formed by two parallel cooperative arms. Based on the application, these arms may loose some degrees of freedom by locking into each other. However, they are considered as redundant arms when operating without any locked joints/links. In this paper, a method is introduced to find the optimal configuration of this manipulator. The objective is to find the configuration in which maximum cooperative force is exerted to an object in a specific direction. The dynamics of the robot is parametrically formulated for different configurations, and by considering the geometrical constraints optimization is performed using fine-mesh and genetic...
Design and Analysis of a Force-Isotropic Underactuated Humanoid Hand
, M.Sc. Thesis Sharif University of Technology ; Zohoor, Hassan (Supervisor)
Abstract
Robots have been widely used for various applications, especially during the last decades. Robots are made of several parts, in which, "Hand" is one of the most important of those. Hands are designed according to their applications and are not necessarily like human ones. Development of humanoid robots, however, brings a special place to human-like hands. In this research, a force-isotropic underactuated finger with two phalanxes and one actuator is designed, considering design limitations and through static analysis. Tendon, cam and mechanical lock (ratchet gear) are among the main components which have been considered in the finger design. Then, a model was fabricated and tested in order...
Extended INFELT STEP: An interoperable platform for managing collaboration among New Product Development applications and CAD/CAM software integrated based on ISO 10303 (STEP) standard
, Article Proceedings of the International MultiConference of Engineers and Computer Scientists 2010, IMECS 2010, 17 March 2010 through 19 March 2010, Kowloon ; 2010 , Pages 1820-1826 ; 9789881701282 (ISBN) ; Houshmand, M ; Sharif University of Technology
2010
Abstract
Today's information technology capabilities enable the enterprises to increase the manufacturing collaboration and interoperability among their different departments. These departments are engaged in different product development processes from design to manufacturing. INFELT STEP is a three-layered platform. These layers have functions and structures that enable the INFELT STEP platform to manage the product development collaboration among different CAD/CAM application software with an integrated product data structure. INFELT STEP has structures and functions in its interoperability layer that enable different CAD/CAM application software and CNC post processors to use their own data...
Kinematic Optimization of The Dual-Arm Cam-Lock Robot
,
Ph.D. Dissertation
Sharif University of Technology
;
Meghdari, Ali
(Supervisor)
;
Sohrabpour, Saeed
(Supervisor)
Abstract
The dual-arm cam-lock robot is a reconfigurable and adaptive robotic arm. The novel design of this robot allows it to manipulate the objects either by cooperation of two completely independent arms, or with locking proper links in each other and featuring the advantages of a parallel manipulator. Depending on the position of the cam-locked links, the robot may lose a few degrees of freedom and gain a different dynamic condition from the view point of the consumed energy, stiffness, dexterity, and etc. So the best configuration of the robot can be selected to perform the desired task, considering all possible configurations of the robot. In this dissertation, formulation and implementation of...
Trajectory Optimization of a Dual-arm Cam-lock Robot Considering Redundancy
, M.Sc. Thesis Sharif University of Technology ; Meghdari, A. (Ali) (Supervisor) ; Ghaemi Osgouie, Kambiz (Supervisor)
Abstract
In the present work, trajectory optimization of the Dual-Arm Cam-Lock robot considering kinematic and dynamic redundancy is performed. First, the optimal control problem is solved only considering kinematic redundancy and then is solved considering dynamic redundancy. General form of the dynamic model for the system is developed using Lagrangian relations. Global optimization method is used for redundancy resolution problem. A performance index is defined based on the consumed kinetic energy and is minimized through a desired trajectory using the global optimization method. Formulations of optimal control problem are derived and initial boundary problem is changed to two point boundary value...
A Novel Digital Dentistry Platform Based on Cloud Manufacturing Paradigm
, Ph.D. Dissertation Sharif University of Technology ; Houshmand, Mahmoud (Supervisor) ; Fatahi Valilai, Omid (Supervisor) ; Vasegh, Zahra (Supervisor)
Abstract
This thesis has developed a novel platform for digital dentistry which facilitates the interoperability among different digital components and improves digital workflow in a collaborative environment. The platform is inspired by the cloud manufacturing paradigm for enabling the interoperability and collaboration management and also applies the DICOM standard to improve the integration for the coordination among the different stakeholders for better sharing of their resources while they are geographically distributed. The paper has proposed the application of the PACS concept to include design, implant planning, process planning and production workstations. The paper has conducted a...
Experimental study of forced convection heat transfer from a cam shaped tube in cross flows
, Article International Journal of Heat and Mass Transfer ; Volume 50, Issue 13-14 , 2007 , Pages 2605-2611 ; 00179310 (ISSN) ; Lavasani, A. M ; Sharif University of Technology
2007
Abstract
An experimental investigation has been conducted to clarify forced convection heat transfer characteristic and flow behavior of an isothermal cam shaped tube in cross flow. The range of angle of attack and Reynolds number based on an equivalent circular tube are within 0° < α < 180° and 1.5 × 104 < Reeq < 2.7 × 104, respectively. The results show that the mean heat transfer coefficient is a maximum at about α = 90° over the whole range of the Reynolds numbers. It is found that thermal hydraulic performance of the cam shaped tube is larger than that of a circular tube with the same surface area except for α = 90° and 120°. Furthermore, the effect of the diameter of the cam shaped tube upon...
Application of Knowledge-based Systems (kbs) in Exchange and Integration Manufacturing Systems Information with Cloud Manufacturing Approach (In Case Cooling Tower)
, M.Sc. Thesis Sharif University of Technology ; Houshmand, Mahmoud (Supervisor)
Abstract
Product knowledge is the most precious asset of any manufacturing company, particularly for OKP companies. High level of customization is one characteristic of OKP which means more customer involvements in OKPPD activities, and customer requirements and expectations may be changing at any activity in PD, e.g., at designing stage. As SMEs, OKP companies always have limitation in resources such as machines tools, human resources, cutters, clamps, so managing the limitations is one of the major challenges that must be faced for maximizing the efficiently and productivity. The part of design that involves fuzzy problems and a lot of product knowledge, it is a critical part for the entire PD. In...
Integration of Design and Manufacturing Systems Using Neutral Data Structure
, Ph.D. Dissertation Sharif University of Technology ; Hooshmand, Mahmoud (Supervisor)
Abstract
In competitive environment of quick market changes, developing an interoperable manufacturing system is a necessity. Process planning as a connection link between design and manufacturing, has never been able to integrate these up/down stream activities and in spite of employing computer systems, CAPP’s information has been managed in an isolated manner. To realize interoperability, the exchange of part and product data must be independent of their platforms. There are two basic approaches for this purpose: i) Utilizing interface and ii) Utilizing neutral formats. STEP (Standard for the Exchange of Product data) plays a significant role as a neutral data model to integrate design,...
Flexible flow line scheduling considering machine eligibility in a digital dental laboratory
, Article International Journal of Production Research ; Volume 58, Issue 21 , 2020 , Pages 6513-6531 ; Fatahi Valilai, O ; Houshmand, M ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
Introduction of digital solutions has made dentistry more efficient and effective in response to patients’ demands. Moreover, digital solution helps participants to manage daily workflow simpler than traditional practices. Scanners, CAD/CAM software, CNC machines and 3D printers are components of digital solutions in current dentistry. Responding to patients as quickly as possible is essential in medical fields and dentistry has similar situations. On the other hand, demands in dentistry are highly customized that it makes managing orders more difficult because each order needs special design and production. Thus, this paper assesses orders in digital dentistry and develops a mathematical...
C-MAN: a Novel Manufacturing Platform Based on Cloud Manufacturing Paradigm
, Ph.D. Dissertation Sharif University of Technology ; Houshmand, Mahmoud (Supervisor)
Abstract
The synergy of fundamental factors like changes in governmental policies, global expansions of the manufacturing industries and improvements in technology related to reliability of manufacturing information flow have created the global manufacturing revolution in the first years of the twenty-first century. The concept of global manufacturing enterprise potentially brings up benefits and opportunities for today’s manufacturing enterprises like reduction of manufacturing costs by utilizing low labor-cost countries, reduction of business risks and introduction of new markets as a new source for enterprise growth. However, it enforces enterprise to endure costs to adopt the global...
A Novel Framework to Enable Optimum Feature based Process Planning based on STEP-NC Standard and CNC Machines
, M.Sc. Thesis Sharif University of Technology ; Houshmand, Mahmoud (Supervisor)
Abstract
In the domain of manufacturing, computer numerically controllers (CNC) technology is a major contributor to the production capacity of the enterprises. The advances in CNC technology coupled with enhancements in computing systems have provided the basis to re-examine the way in which computer-aided systems (CAx) can be used to enable global manufacturing. Interoperability of the various components of the CAx chain is therefore a major prerequisite for manufacturing enterprises for becoming strategically agile and consequently globally competitive. Being interoperable, resources can be utilized interchangeably in a plug-and-produce manner. Over the last 8years the eminence of a STEP...
, M.Sc. Thesis Sharif University of Technology ; Hoshmand, Mahmoud (Supervisor)
Abstract
Integrated design includes CAD, process planning and CNC code generation based on an integrated data structure. To enable different CAD/CAM software solutions to be interoperable, it is required to support data exchange in manufacturing enterprises. To realize interoperability there are two basic approaches: i. to focus on STEP standard to support data exchange between CAD systems as well as CAPP/CAM and CNC machining systems; the use of STEP standard ensures the data integration based on STEP standard. ii. utilizing a platform consists of structures and procedures to enable exchange of data between different CAD/CAM/CAPP software applications seamlessly. In this article, the important...
Optimization of Kinematic Redundancy and Manipulability Analysis of a Dual-Arm Cam-Lock Robot
, M.Sc. Thesis Sharif University of Technology ; Ghaemi Osguei, Kambiz (Supervisor) ; Meghdari, Ali ($item.subfieldsMap.e)
Abstract
Cooperative systems have been widely studied in literature. The Dual-Arm Cam-Locked (DACL) robot manipulators are reconfigurable arms formed by two parallel cooperative manipulators which operate redundantly but they may lock into each other in specific joints to increase structural stiffness in the cost of losing some degrees of freedom. Obtaining the optimal configuration demands lots of computational time and is not practical in real-time applications. In the present work, considering the kinematics of the manipulator, the optimal control problem of redundancy is formulated in the framework of tasks with the order of priority. The optimal control formulation is derived by using the...
INFELT STEP: An integrated and interoperable platform for collaborative CAD/CAPP/CAM/CNC machining systems based on STEP standard
, Article International Journal of Computer Integrated Manufacturing ; Volume 23, Issue 12 , 2010 , Pages 1095-1117 ; 0951192X (ISSN) ; Houshmand, M ; Sharif University of Technology
Abstract
Integrated product development is comprised of CAD, process planning and CNC code generation based on an integrated data structure. To make various CAD/CAM software solutions with different internal product data structures interoperable, it is necessary to realise reliable and robust information exchange capability in a manufacturing environment. To enable interoperability amongst integrated product development processes, management of collaboration of diverse CAD/CAM software packages is of outmost importance. In this article, the fundamental requirements for achieving interoperability and collaboration management in an integrated, enterprise-wide, product development process environment...
Introducing a roadmap to implement the universal manufacturing platform using axiomatic design theory
, Article International Journal of Manufacturing Research ; Volume 5, Issue 2 , 2010 , Pages 252-269 ; 17500591 (ISSN) ; Houshmand, M ; Sharif University of Technology
2010
Abstract
In competitive environment of quick market changes, developing an interoperable manufacturing system is a necessity. To realise interoperability, the exchange of part and product data must be independent of their platforms. There are two basic approaches for this purpose: i utilising interfaces ii utilising neutral formats. Standard for the Exchange of Product data (STEP) plays a significant role as a neutral data model to integrate design, manufacturing and other activities in product life cycle. To implement a Universal Manufacturing Platform (UMP), a systematic roadmap is required. The current paper proposes such a roadmap using the methodology of Axiomatic Design (AD)
Optimal configuration of dual-arm cam-lock robot based on task-space manipulability
, Article Robotica ; Volume 27, Issue 1 , 2009 , Pages 13-18 ; 02635747 (ISSN) ; Meghdari, A ; Sohrabpour, S ; Sharif University of Technology
2009
Abstract
In this paper obtaining the optimal configuration of the dual-arm cam-lock (DACL) robot at a specific point is addressed. The objective is to optimize the applicable task-space force in a desired direction. The DACL robot is a reconfigurable manipulator formed by two parallel cooperative arms. The arms normally operate redundantly but when needed, they can lock into each other in certain joints in order to achieve a higher stiffness, while losing some degrees of freedom. Furthermore, the dynamics of the DACL robot is discussed and parametrically formulated. Considering the geometrical constraints at a given point in the robot's workspace, the optimum configuration for maximizing the...
An overview on five approaches for translating cad data into manufacturing information
, Article Journal of Advanced Manufacturing Systems ; Volume 8, Issue 1 , 2009 , Pages 89-114 ; 02196867 (ISSN) ; Mokhtar, A ; Hayasi, M ; Kamrani, A ; Nasr, E. A ; Sharif University of Technology
2009
Abstract
All Rapid Prototyping and CNC material removal processes use information which is extracted from a CAD system. There are several ways to convert CAD data into usable manufacturing information. In this paper, five methods of translating CAD data into a usable manufacturing format are explained. These five methods are data translation from CAD files in STL, DXF, STEP-NC, and IGES formats as well as a platform-dependent area method of manufacturing information in a desirable format. For each method, algorithms and details about the CAD data translation into usable manufacturing and prototyping processes formats are presented. Finally, applications of each approach and its pros and cons are...
A novel digital dentistry platform based on cloud manufacturing paradigm
, Article International Journal of Computer Integrated Manufacturing ; Volume 32, Issue 11 , 2019 , Pages 1024-1042 ; 0951192X (ISSN) ; Fatahi Valilai, O ; Houshmand, M ; Vasegh, Z ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
Dentistry technology has been developed drastically during past two decades and the application of software and automated digital equipment have been proposed to have the most influence. Digital dental workflow includes four phases: scan, design, production planning and production which in each of the phases, the various software packages and digital devices are required. In addition, workflow in dentistry requires intensive cooperation among dentists, dental laboratories, technicians, imaging and production centres. This paper has developed anovel platform for digital dentistry, which facilitates the interoperability among different digital components and improves digital workflow in...
Pressure loss and heat transfer characterization of a cam-shaped cylinder at different orientations
, Article Journal of Heat Transfer ; Volume 130, Issue 12 , September , 2008 , Pages 1-4 ; 00221481 (ISSN) ; Lavasani, A. M ; Sharif University of Technology
2008
Abstract
Pressure drag coefficient and heat transfer are experimentally investigated around a single noncircular cylinder in cross-flow under angle of attack 0 deg<α>360 deg and Reynolds number 1.5*104