A Model for Multi-Input Mechanical Advantage in Origami-Based Mechanisms

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Jared Butler ◽  
Landen Bowen ◽  
Eric Wilcox ◽  
Adam Shrager ◽  
Mary I. Frecker ◽  
...  
Keyword(s):  
Experimental Data ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Magnetic Actuation ◽  
Complex Mechanism ◽  
Mechanical Advantage ◽  
Single Output ◽  
Multiple Input ◽  
Engineering Problems ◽  
Single Input

Mechanical advantage is traditionally defined for single-input and single-output rigid-body mechanisms. A generalized approach for identifying single-output mechanical advantage for a multiple-input compliant mechanism, such as many origami-based mechanisms, would prove useful in predicting complex mechanism behavior. While origami-based mechanisms are capable of offering unique solutions to engineering problems, the design process of such mechanisms is complicated by the interaction of motion and forces. This paper presents a model of the mechanical advantage for multi-input compliant mechanisms and explores how modifying the parameters of a model affects their behavior. The model is used to predict the force-deflection behavior of an origami-based mechanism (Oriceps) and is verified with experimental data from magnetic actuation of the mechanism.

Decomposition Strategies for the Synthesis of Single Input-Single Output and Dual Input-Single Output Compliant Mechanisms

2007 ◽  
Author(s):  
Charles Kim
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Single Point ◽  
Building Blocks ◽  
New Method ◽  
Single Input Single Output ◽  
Single Output ◽  
Alternative Method ◽  
Decomposition Strategies ◽  
Single Input

In this paper a new method for the synthesis of compliant mechanism topologies is presented which involves the decomposition of motion requirements into more easily solved sub-problems. The decomposition strategies are presented and demonstrated for both single input-single output (SISO) and dual input-single output (DISO) planar compliant mechanisms. The methodology makes use of the single point synthesis (SPS) which effectively generates topologies which satisfy motion requirements at one point by assembling compliant building blocks. The SPS utilizes compliance and stiffness ellipsoids to characterize building blocks and to combine them in an intelligent manner. Both the SISO and DISO problems are decomposed into sub-problems which may be addressed by the SPS. The decomposition strategies are demonstrated with illustrative example problems. This paper presents an alternative method for the synthesis of compliant mechanisms which augments designer insight.

Design of Multimaterial Compliant Mechanisms Using Level-Set Methods

2005 ◽  
Vol 127 (5) ◽  
pp. 941-956 ◽  
Author(s):  
Michael Yu Wang ◽  
Shikui Chen ◽  
Xiaoming Wang ◽  
Yulin Mei
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Level Set Methods ◽  
Single Output ◽  
Geometric Boundary ◽  
Single Input ◽  
Applied Forces ◽  
Multiple Materials

A monolithic compliant mechanism transmits applied forces from specified input ports to output ports by elastic deformation of its comprising materials, fulfilling required functions analogous to a rigid-body mechanism. In this paper, we propose a level-set method for designing monolithic compliant mechanisms made of multiple materials as an optimization of continuum heterogeneous structures. Central to the method is a multiphase level-set model that precisely specifies the distinct material regions and their sharp interfaces as well as the geometric boundary of the structure. Combined with the classical shape derivatives, the level-set method yields an Eulerian computational system of geometric partial differential equations, capable of performing topological changes and capturing geometric evolutions at the interface and the boundary. The proposed method is demonstrated for single-input and single-output mechanisms and illustrated with several two-dimensional examples of synthesis of multimaterial mechanisms of force inverters and gripping and clamping devices. An analysis on the formation of de facto hinges is presented based on the shape gradient information. A scheme to ensure a well-connected topology of the mechanism during the process of optimization is also presented.

Conceptual Insightful Synthesis of Spatial Compliant Mechanisms Using the Load Flow Formulation

2019 ◽  
Vol 142 (5) ◽  
Author(s):  
Girish Krishnan ◽  
Sree Kalyan Patiballa
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Building Blocks ◽  
Load Flow ◽  
Load Path ◽  
Single Input Single Output ◽  
Single Output ◽  
Load Paths ◽  
Single Input ◽  
Computationally Intensive

Abstract Conceptual design of spatial compliant mechanisms with distinct input and output ports may be hard because of its complex interconnected topology and is currently accomplished by computationally intensive automated techniques. This paper proposes a user insightful method for generating conceptual compliant topology solutions. The method builds on recent advances where the compliant mechanism deformation is represented as load flow in its constituent members. The nature of load flow enables functional decomposition of compliant mechanisms into maximally decoupled building blocks, namely, a transmitter member and a constraint member. The proposed design methodology seeks to synthesize spatial compliant designs by systematically combining transmitter-constraint members first, identifying kinematically feasible transmitter load paths between input(s) and output(s), and then selecting appropriate constraints that enforce the load path. The paper proposes four design steps to generate feasible solutions and four additional guidelines to optimize load paths and constraint orientations. The method is applied with equal ease to three spatial complaint mechanism examples that belong to single-input single-output, multiple-input single output, and single-input multiple-output mechanisms.

Estimation Design Using Youla Parametrization With Automotive Applications

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Francis Assadian ◽  
Alex K. Beckerman ◽  
Jose Velazquez Alcantar
Keyword(s):  
Kalman Filtering ◽  
Feedback Stabilization ◽  
Estimation Technique ◽  
Single Input Single Output ◽  
Normal Forces ◽  
Single Output ◽  
Multiple Input ◽  
Single Input ◽  
Established Technique ◽  
Better Than

Youla parametrization is a well-established technique in deriving single-input single-output (SISO) and, to a lesser extent, multiple-input multiple-ouput (MIMO) controllers (Youla, D., Bongiorno, J. J., Jr., and Lu, C., 1974, “Singleloop Feedback-Stabilization of Linear Multivariable Dynamical Plants,” Automatica, 10(2), pp. 159–173). However, the utility of this methodology in estimation design, specifically in the framework of controller output observer (COO) (Ozkan, B., Margolis, D., and Pengov, M., 2008, “The Controller Output Observer: Estimation of Vehicle Tire Cornering and Normal Forces,” ASME J. Dyn. Syst., Meas., Control, 130(6), p. 061002), is not established. The fundamental question to be answered is as follows: is it possible to design a deterministic estimation technique using Youla paramertization with the same robust performance, or better, than well-established stochastic estimation techniques such as Kalman filtering? To prove this point, at this stage, a comparative analysis between Youla parametrization in estimation and Kalman filtering is performed through simulations only. In this paper, we provide an overview of Youla parametrization for both control and estimation design. We develop a deterministic SISO and MIMO Youla estimation technique in the framework of COO, and we investigate the utility of this method for two applications in the automotive domain.

Load-Flow Based Design of Compliant Mechanisms With Embedded Soft Actuators

2019 ◽  
Author(s):  
Sree Kalyan Patiballa ◽  
Sreeshankar Satheeshbabu ◽  
Girish Krishnan
Keyword(s):  
Embedded System ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Flow Behavior ◽  
Load Flow ◽  
Mechatronic Systems ◽  
Soft Systems ◽  
Single Input Single Output ◽  
Single Output ◽  
Compliant Systems

Abstract Transmission members such as gears and linkages are ubiquitously used in mechatronic systems to tailor the performance of actuators. However, in most bio-inspired soft systems the actuation and transmission members are closely integrated, and sometimes indistinguishable. Embedded actuation is greatly advantageous for attaining high stroke and transferring large output forces. This paper attempts at a systematic synthesis of compliant systems with embedded contractile actuators and passive members to achieve a particular kinematic objective. The paper builds on recent understanding of a compliant mechanism topology where the constituent members can be functionally classified as load transferring transmitters and strain energy storing constraints. The functional equivalence between the transmitter members and actuators are used to replace transmitters in tension with contractile actuators, thus realizing a compliant embedded system. Once a single-input single-output compliant mechanism is designed, and its load flow behavior mapped, systematic guidelines and best practices are established for embedding actuators within the topology to increase performance without altering the kinematic behavior. Several examples, including a prototype that used soft pneumatic artificial muscles is presented to validate the synthesis framework. The initial results will form the basis for designing fully autonomous compliant systems with embedded actuators and sensors without the use of computationally expensive techniques.

Topology Optimization of Compliant Mechanisms Explicitly Considering Desired Kinematics and Stiffness Constraints

2016 ◽  
Author(s):  
Alexander Hasse
Keyword(s):  
Strain Energy ◽  
Compliant Mechanisms ◽  
Single Input Single Output ◽  
Output Displacement ◽  
Single Output ◽  
Input And Output ◽  
Optimization Formulation ◽  
Topology And Shape Optimization ◽  
Optimization Parameters ◽  
Single Input

A mechanism is designed to transform forces and/or displacements from an input to one or multiple outputs. This transformation is essentially ruled by the kinematics, i.e. the defined ratio between input and output displacements. Although the kinematics forms the basis for the design of conventional mechanisms, approaches for the topology and shape optimization of compliant mechanisms do not normally explicitly include the kinematics in their optimization formulation. The kinematics is more or less an outcome of the optimization process. A defined kinematics can only be realized by iteratively adjusting process-specific optimization parameters within the optimization formulation. Moreover, existing approaches normally minimize the strain energy that is stored in the compliant mechanisms according to a defined input and output displacement — although in some applications a certain amount of strain energy is required. This paper presents a new optimization formulation that solves the aforementioned problems. It is based on the principles of designing compliant mechanisms with selective compliance formerly presented by the author. The formulation is derived by means of an intensive workup of the design problem of compliant mechanisms. The method is validated for different design examples ranging from standard single-input/single-output mechanisms (force inverters) to multi-output mechanisms (shape-adaptive structures).

A Blended Empirical Shot Stream Velocity Model for Improvement of Shot Peening Production

2021 ◽  
Author(s):  
VAN BO NGUYEN ◽  
Augustine Teo ◽  
Te Ba ◽  
Ampara Aramcharoen ◽  
Kunal Ahluwalia ◽  
...  
Keyword(s):  
Experimental Data ◽  
Real Time ◽  
Measurement Data ◽  
Velocity Model ◽  
Stream Velocity ◽  
Single Output ◽  
Single Input ◽  
Online Tracking ◽  
Optimal Process Control

Abstract Peening intensity and coverage are vital measurement outputs to quantify the quality of a peening process in surface enhancement operation of metal parts. In practice, these parameters can only be measured offline upon process completion, which are not suitable for online tracking and operation. Instead, shot stream velocity can be used as a real-time monitoring parameter to bridge operational inputs to the outputs. As such, a robust and accurate shot stream velocity model is needed for real-time tracking. In this study, we propose a blended practical model for shot stream velocity to address the issues. The model is constructed using regression algorithm based on the blended candidate functions, which are developed from experimental data and nature of the particle-air flow inside the system. Obtained model is validated against experimental data for different conditions. Calculated velocities are in good agreement with the measurements. In addition, applications of the model in predicting the shot stream velocity for different peen types, different peening intensities and coverages. The obtained results are comparable to the measurement data. Furthermore, a single-input and single-output model-based control is developed from proposed shot stream velocity model. The developed control system is robust, accurate and reliable. It implies that the developed model can be used to provide necessary information as well as in optimal process control development to improve and accelerate the peening processes to reduce cost and time of actual productions.

An Alternative Approach to Mechanical Advantage for the Analysis of a Multiple-Input Multiple-Output Mechanical Device

1992 ◽  
Author(s):  
M. M. Ogot ◽  
B. J. Gilmore
Keyword(s):  
Multiple Input Multiple Output ◽  
Output Port ◽  
Mechanical Advantage ◽  
Single Input Single Output ◽  
Input Force ◽  
Alternative Approach ◽  
Output Force ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Single Input

Abstract The design efficiency of mechanical systems has traditionally been measured via mechanical advantage (MA) which relates the amount of force exerted at the output to the corresponding force applied at the input. MA has been confined to single-input single-output devices, and only recently to single-input multiple-output port devices. This paper presents an alternative approach to MA. The classical definition of MA required the input force to do work on the mechanism, and the output force to be worked on by the mechanism. However this may cause problems where the external loads flip back and forth between doing work to and being worked on by the mechanism at different points in the cycle. This paper overcomes this difficulty by considering the input force as that applied by the mechanism actuator, and the output force to be the external or applied load. With these definitions, a general expression for MA applicable to multiple-input, multiple-output port mechanisms is presented.

Sign in / Sign up

Export Citation Format

Share Document