Synthesizing Soft Parallel Robots Comprised of Active Constraints

2014 ◽  
Author(s):  
Jordan Rivera ◽  
Jonathan B. Hopkins ◽  
Charles Kim
Keyword(s):  
Case Studies ◽  
Degrees Of Freedom ◽  
Parallel Systems ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Soft Robot ◽  
Active Constraints ◽  
New Type ◽  
Constraint Topologies ◽  
Synthesis Approach

In this paper, we introduce a new type of spatial parallel robot that is comprised of soft inflatable constraints called Tri-Chamber Actuators (TCAs). We extend the principles of the Freedom and Constraint Topologies (FACT) synthesis approach to enable the synthesis and analysis of this new type of soft robot. The concepts of passive and active freedom spaces are introduced and applied to the design of general parallel systems that consist of active constraints (i.e., constraint that can be actuated to impart various loads onto the system’s stage) that both drive desired motions and guide the system’s desired degrees of freedom (DOFs). We provide the fabrication details of the TCA constraints introduced in this paper and experimentally validate their FACT-predicted kinematics. Examples are provided as case studies.

Synthesis and Analysis of Soft Parallel Robots Comprised of Active Constraints

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Jordan Rivera ◽  
Charles Kim ◽  
Girish Krishnan
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Soft Robot ◽  
Element Analysis ◽  
Active Constraints ◽  
New Type ◽  
Constraint Model ◽  
Constraint Topologies ◽  
Synthesis Approach

In this paper, we introduce a new type of spatial parallel robot that is comprised of soft inflatable constraints called trichamber actuators (TCAs). We extend the principles of the freedom and constraint topologies (FACT) synthesis approach to enable the synthesis and analysis of this new type of soft robot. The concepts of passive and active freedom spaces are introduced and applied to the design of general parallel systems that consist of active constraints (i.e., constraint that can be actuated to impart various loads onto the system's stage) that both drive desired motions and guide the system's desired degrees of freedom (DOFs). We provide the fabrication details of the TCA constraints introduced in this paper and experimentally determine their appropriate FACT-based constraint model. We fabricate a soft parallel robot that consists of three TCA constraints and verify and validate its FACT-predicted performance using finite element analysis (FEA) and experimental data. Other such soft robots are synthesized using FACT as case studies.

Synthesizing Parallel Flexures That Mimic the Kinematics of Serial Flexures Using Freedom and Constraint Topologies

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Jonathan B. Hopkins
Keyword(s):  
Case Studies ◽  
Degrees Of Freedom ◽  
General Purpose ◽  
Complete List ◽  
Geometric Shapes ◽  
Point Of Interest ◽  
Precision Motion ◽  
Constraint Topologies ◽  
Synthesis Approach

The principles of the freedom and constraint topologies (FACT) synthesis approach are adapted and applied to the design of parallel flexure systems that mimic degrees of freedom (DOFs) primarily achievable by serial flexure systems. FACT provides designers with a comprehensive library of geometric shapes. These shapes enable designers to visualize the regions wherein compliant flexure elements may be placed for achieving desired DOFs. By displacing these shapes far from the point of interest of the stage of a flexure system, designers can compare a multiplicity of concepts that utilizes the advantages of both parallel and serial systems. A complete list of which FACT shapes mimic which DOFs when displaced far from the point of interest of the flexure system's stage is provided as well as an intuitive approach for verifying the completeness of this list. The proposed work intends to cater to the design of precision motion stages, optical mounts, microscopy stages, and general purpose flexure bearings. Two case studies are provided to demonstrate the application of the developed procedure.

Analyzing and Designing Serial Flexure Elements

2013 ◽  
Author(s):  
Jonathan B. Hopkins
Keyword(s):  
Case Studies ◽  
Degrees Of Freedom ◽  
Compliant Mechanisms ◽  
Rigid Bodies ◽  
The Other ◽  
Geometric Shapes ◽  
Other Hand ◽  
Constraint Topologies ◽  
Synthesis Approach

In this paper we introduce the principles necessary to analyze and design serial flexure elements, which may be used to synthesize advanced compliant mechanisms (CMs). The most commonly used flexure elements (e.g., wire, blade, or living hinge flexures) are often parallel and thus impose constraining forces directly through all parts of their geometry to the rigid bodies that they join within the CM. Serial flexure elements, on the other hand, constrain rigid bodies with a larger variety of forces and moments and thus enable CMs to achieve (i) more degrees of freedom (DOFs), (ii) larger dynamic and elastomechanic versatility, and (iii) greater ranges of motion than parallel elements. In this paper, we extend the principles of the Freedom and Constraint Topologies (FACT) synthesis approach such that it enables the synthesis of CMs that are not only constrained by parallel flexure elements, but also by serial elements. FACT utilizes geometric shapes to intuitively guide designers in visualizing compliant element geometries that achieve any desired set of DOFs. In this way, designers can rapidly generate a host of new serial flexure elements for various CM applications. Such elements are provided here as case studies.

scholarly journals Designing hybrid flexure systems and elements using Freedom and Constraint Topologies

2013 ◽  
Vol 4 (2) ◽  
pp. 319-331 ◽  
Author(s):  
J. B. Hopkins
Keyword(s):  
Hybrid Systems ◽  
Case Studies ◽  
Degrees Of Freedom ◽  
Rigid Bodies ◽  
Geometric Shapes ◽  
Design Requirements ◽  
Constraint Topologies ◽  
Exact Constraint ◽  
Synthesis Approach

Abstract. In this paper we introduce the principles necessary to synthesize hybrid flexure systems and elements. Flexure systems consist of rigid bodies that are joined together by flexure elements that elastically deform to guide the system's rigid bodies with desired degrees of freedom (DOFs). The principles introduced here for synthesizing hybrid flexure systems and elements are extensions of the Freedom and Constraint Topologies (FACT) synthesis approach. FACT utilizes a comprehensive library of geometric shapes from which designers can rapidly consider and compare a multiplicity of flexure concepts that achieve any desired set of DOFs. Prior to this paper, designers primarily used these shapes to synthesize parallel and serial flexure systems and elements. With this paper, designers may now use these same shapes to synthesize more general flexures that consist of various combinations of parallel and serial systems and elements (i.e., hybrid configurations). As such, designers can access a larger body of flexure solutions that satisfy demanding design requirements. Instructions for helping designers utilize or avoid the advantages and challenges of over-, under-, and exact-constraint are also provided. Hybrid systems and elements are analysed and designed as case studies.

A Visualization Approach for Analyzing and Synthesizing Serial Flexure Elements

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Jonathan B. Hopkins
Keyword(s):  
Case Studies ◽  
Degrees Of Freedom ◽  
Rigid Bodies ◽  
Negative Effects ◽  
Constraint Topologies ◽  
Synthesis Approach

In this paper, we extend the principles of the freedom and constraint topologies (FACT) synthesis approach such that designers can analyze and synthesize serial flexure elements—not to be confused with serial flexure systems. Unlike serial systems, serial elements do not possess intermediate rigid bodies within their geometry and thus avoid the negative effects of unnecessary mass and underconstrained bodies that generate uncontrolled vibrations. Furthermore, in comparison with other common parallel flexure elements such as wire, blade, and living hinge flexures, serial elements can be used within flexure systems to achieve (i) a larger variety of kinematics, (ii) more dynamic and elastomechanic versatility, and (iii) greater ranges of motion. Here, we utilize the principles of FACT to intuitively guide designers in visualizing a multiplicity of serial flexure element geometries that can achieve any desired set of degrees of freedom (DOFs). Using this approach, designers can rapidly generate a host of new serial flexure elements for synthesizing advanced flexure systems. Thirty seven serial flexure elements are provided as examples, and three flexure systems that consist of some of these elements are synthesized as case studies.

Modelling and Simulation of a Isoglide T3R1 Parallel Robot

2010 ◽  
Vol 166-167 ◽  
pp. 457-462
Author(s):  
Dan Verdes ◽  
Radu Balan ◽  
Máthé Koppány
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Practical Implementation ◽  
Medical Robots ◽  
The Past ◽  
And Control ◽  
Workspace Design ◽  
Human Systems

Parallel robots find many applications in human-systems interaction, medical robots, rehabilitation, exoskeletons, to name a few. These applications are characterized by many imperatives, with robust precision and dynamic workspace computation as the two ultimate ones. This paper presents kinematic analysis, workspace, design and control to 3 degrees of freedom (DOF) parallel robots. Parallel robots have received considerable attention from both researchers and manufacturers over the past years because of their potential for high stiffness, low inertia and high speed capability. Therefore, the 3 DOF translation parallel robots provide high potential and good prospects for their practical implementation in human-systems interaction.

Construction of a Six-Degrees-of-Freedom Parallel Manipulator With Three Planarly Actuated Links

1996 ◽  
Author(s):  
Ronen Ben-Horin ◽  
Moshe Shoham
Keyword(s):  
Parallel Manipulator ◽  
High Performance ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Simple Design ◽  
Output Link ◽  
Coordinated Motion ◽  
Six Degrees Of Freedom ◽  
Work Volume ◽  
New Type

Abstract The construction of a new type of a six-degrees-of-freedom parallel robot is presented in this paper. Coordinated motion of three planar motors, connected to three fixed-length links, produces a six-degrees-of-freedom motion of an output link. Its extremely simple design along with much larger work volume make this high performance-to-simplicity ratio robot very attractive.

Type synthesis of coordinated multi-robot system based on parallel thought

2018 ◽  
Vol 42 (2) ◽  
pp. 164-176 ◽  
Author(s):  
Wanqiang Xi ◽  
Bai Chen ◽  
Yaoyao Wang ◽  
Feng Ju
Keyword(s):  
Degrees Of Freedom ◽  
Screw Theory ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Type Synthesis ◽  
World Coordinate System ◽  
Coordination System ◽  
Branched Chain ◽  
Branched Chains ◽  
Multi Robot

For the synthesis of the required type about the multi-robot coordination system in industrial transportation, this paper presents a novel method in which each robot in the coordinated task is viewed as a branched chain of an equivalent parallel robot (EPR), which is converted into a problem for type synthesis of parallel robots. A theoretic method is proposed to represent the kinematic features of the mechanism’s end-effector and its position and pose in the world coordinate system. The basic concept of a robotic characteristic (C) set is given, and the corresponding algorithm is analyzed. Based on the theory of C set, the concrete steps for type synthesis of EPR are presented by analyzing the characteristics of its branched chains, and many EPR groups with end kinematic features for the C sets of the operational tasks are obtained. Then three translational (3T) operational requirements that can be extended to other degrees of freedom (DOF) are adopted, and the DOF of homogeneous and heterogeneous EPR are analyzed using screw theory. Finally the validation of the method is demonstrated by Adams, which shows that the two groups are able to complete the task.

scholarly journals Kinematics analysis of a new parallel robotics

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142091995
Author(s):  
Shi Baoyu ◽  
Wu Hongtao
Keyword(s):  
Degrees Of Freedom ◽  
Screw Theory ◽  
Parallel Robot ◽  
Virtual Prototype ◽  
Motion Platform ◽  
Closed Form Solutions ◽  
New Type ◽  
Virtual Prototype Technology ◽  
Parallel Robotics ◽  
D Model

A new type of parallel robot ROBO_003 is presented. Its mechanisms, kinematics, and virtual prototype technology are introduced. The research of degrees of freedom (DOF) is based on screw theory, a set of screw is separated as a branch, which named as constrain screw. The type of three DOF gained by counting constrain screw, the moving platform’s frame, and base platform’s frame is set, respectively, a complete kinematic research including closed-form solutions for direct kinematic problem. The 3-D model of ROBO_003 is established using SOLIDWORKS; position and orientation of motion platform can be gained using ADMAS, which is a type of virtual prototype technology. The resultant shows that the structure of ROBO_003 is reasonable, three DOF of motion platform can be operated in a reasonable range, the solutions to the direct kinematics are right, and robot ROBO_003 can be used in many industrial fields. The research of this article provides a basis for the practical application of parallel robotics ROBO_003.

Kinematic Analysis of a Five-Legged Mobile Robot

2010 ◽  
Author(s):  
Muhammed R. Pac ◽  
Dan O. Popa
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Parallel Robots ◽  
The Body ◽  
Legged Robots ◽  
Upper Body ◽  
Design Changes ◽  
Robot Performance ◽  
The Impact

Legged robots are more maneuverable, and can negotiate rough terrain much better than conventional locomotion using wheels. However, since the kinematic or dynamic analysis of such robots involves closed chains, it is typically more difficult to investigate the impact of design changes, such as the number, or the design of its legs, to robot performance. Most legged robots consist of 4 legs (quadrupeds) or 6 legs (hexapods). This paper discusses the kinematic analysis of an unconventional, symmetrical 5-legged robot with 2-DOF (Degrees Of Freedom) universal joints in each leg. The analysis was carried out in order to predict the mobility of the upper body platform, and investigate the number of robot actuators needed for mobility. The product of exponentials formulation with respect to the local coordinate frames is used to describe the twists of the joints. The analysis is based on the idea that the robot body platform along with the legs can be considered instantaneously as a parallel robot manipulating the ground. Hence, the analysis can be done using the Jacobian formulation of parallel robots. Simulation results confirm the mobility analysis that the robot can have at most 3-DOF for the body and that these freedoms are coupled rotations and translations in 3D space also with a dependence on the configuration of the robot.

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