bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the Theory of Envelope to the Determination of Camoid Profiles With Translating Followers
Authors: Tsay Der Min , Hwang Guan Shyong 
Published: March 2021

Abstract
A new, simple procedure employing the theory of envelope for a family of surfaces with two independent parameters to determine the profiles of camoids with translating spherical followers is presented. Given the follower motion program, the method enables the camoid surface coordinates to be easily generated in an analytical expression. The results are then compared to those obtained by utilizing the principle of contact point between the camoid and the follower surfaces. The pressure angle is analyzed, and the cutter paths required in the machining process are also produced. A numerical example is given to illustrate the application of the approach.
Graphical Synthesis for Limit Positions of a Four-Bar Mechanism Using the Triangle Inequality Concept
Authors: Norton Tony W. , Midha Ashok , Howell Larry L. 
Published: March 2021

Abstract
An innovative methodology is presented for a set of synthesis problems in which the mobility angle between limit positions of a side link of a four-bar mechanism is necessarily prescribed. The principles used in synthesis are derived from a graphical interpretation of the triangle inequality concept. The derived principles give valuable insight to the solution space by dividing it into two separate regions. One region yields only Grashofian mechanisms, and the other region yields only Non-Grashofian mechanisms. This information gives the designer a method for generating all possible mechanisms which satisfy the limit position and mechanism type constraints. A major advantage of the graphical technique is that it uses simple geometric objects, and therefore it can be easily implemented on most CAD packages. Several examples are used to demonstrate the concepts.
Criteria for the Design of High Efficiency Planocentric Transmissions
Authors: Jáuregui Juan Carlos , Sansalvador Rodrigo López 
Published: March 2021

Abstract
In this paper, the design criteria for high efficiency planocentric transmissions is presented. The space solution of a single stage planocentric transmission is limited by geometric constraints. These constraints are produced basically by the interference between pinion teeth and gear teeth. Special interest is focused on the interferences of internal gears and a detailed analysis of the influence of teeth parameters, such as addendum coefficient and pressure angle, is included. Conclusions are drawn from the analysis of the interferences and a design criteria is outlined. It was found that the space solution can be wider if pinion and gear are designed with stub teeth and high pressure angle.
On the Dynamic Analysis of Roller Chain Drives: Part I — Theory
Authors: Veikos Nicholas M. , Freudenstein Ferdinand 
Published: March 2021

Abstract
A generally applicable, computer-aided procedure has been developed for the dynamic analysis of roller chain drives. This approach addresses important factors of chain dynamic behavior such as impact, discontinuities in span length, chain elasticity, coupling between longitudinal and transverse motions, as well as coupling between motion and boundary conditions. The procedure has been used to study various chain configurations. The results show good agreement with experimental observations and indicate some general trends, which provide additional insight into the dynamic behavior of these systems.
On the Dynamic Analysis of Roller Chain Drives: Part II — Case Study
Authors: Veikos Nicholas M. , Freudenstein Ferdinand 
Published: March 2021

Abstract
Part I of this paper (5) summarized the previous work and has described the theoretical and computational aspects of a computer-aided procedure which has been developed by the authors for the dynamic analysis of roller chain drives. Lagrange’s equations of motion have been derived by assuming the roller chain to behave as a series of masses lumped at the roller centers and connected by bars of constant axial stiffness. The equations of motion are solved in the time domain until steady state conditions are achieved.
Use of Resultant in the Dimensional Synthesis of Linkage Components: Motion Generation With Prescribed Timing
Authors: Lin Chuen-Sen , Jia Bao-Ping 
Published: March 2021

Abstract
Resultant theory is applied to derive closed-form solutions for the dimensional synthesis of linkage components for a finite number of precision positions for motion generation with prescribed timing. The solutions are in forms of polynomial equations of the exponential of a single unknown angular displacement. The degree of the derived polynomial depends on the number of links in the linkage component and the number of precision positions to be synthesized for, or the number of compatibility equations. The resultant theory is discussed in detail, and the procedure for the derivation of resultant polynomials is demonstrated. This paper shows that, for the case of two compatibility equations, the solution is a six-degree polynomial. For the case of three compatibility equations, the solution is a fifty-fourth degree polynomial. The Bernshtein formula is applied to check the exact number of solutions of the original system of polynomial equations and to verify the validity of the derived resultant polynomials. An algorithm is also proposed for screening out extra solutions which may be generated through the solution process.
Constrained Optimization of Multi-Degree-of-Freedom Mechanisms for Near-Time Optimal Motions
Authors: Sundar Satish , Shiller Zvi 
Published: March 2021

Abstract
This paper presents a design method of multi-degree-of-freedom mechanisms for near-time optimal motions. The design objective is to select system parameters, such as link lengths and actuator sizes, so as to minimize the optimal motion time of the mechanism along a given path. The exact time optimization problem is approximated by a simpler procedure that maximizes the acceleration near the end points. Representing the directions of maximum acceleration with the acceleration lines, and the reachability constraints as explicit functions of the design parameters, we transform the constrained optimization to a simpler curve fitting problem that can be formulated analytically. This allows the use of efficient gradient type optimizations, instead of the pattern search optimization that is otherwise required. Examples for optimizing the dimensions of a five-bar planar mechanism demonstrate close correlation of the approximate with the exact solutions, and an order of magnitude better computational efficiency than the previously developed unconstrained optimization methods.
A Unified Theory for Kinematic Synthesis
Authors: James Paul A. , Roth Bernard 
Published: March 2021

Abstract
In this paper we derive an analytic method for obtaining infinitesimal kinematic synthesis results as a limiting process from finitely-separated position kinematics. Expanding on previous work, we extend the unified theory to include spatial kinematic synthesis and we present a new numerical method. These new methods serve to unify finite, infinitesimal, and hybrid kinematic synthesis into one theory for kinematic synthesis.
A Singularity-Free Penalty Formulation for the Dynamics of Constrained Multibody Systems
Authors: Avello A. , Bayo E. 
Published: March 2021

Abstract
In a singular position, the number of degrees of freedom of a mechanism instantaneously increases, which is detected by a sudden loss of rank in the jacobian matrix. This rank-deficiency causes the failure of the classical dynamic formulations. The enforcement of the constraints through a penalty method leads to an attractive and efficient dynamic formulation that, in addition, can be used at singularities. This formulation leads to a symmetric and positive definite matrix whose rank does not depend on the rank of the jacobian and thus is ideally suited for singular positions. A refinement of this approach is achieved through an augmented Lagrangian method. A simple example and two dynamic simulations show the effectiveness of the formulation.
Using Singular Value Decomposition in the Analysis of Over and Underconstrained Mechanisms
Authors: Gutkowski L. J. 
Published: March 2021

Abstract
A method for analyzing mechanisms using Singular Value Decomposition is presented. This approach provides a general technique in which all mechanisms (including planar ones) can be analyzed as spatial without numerical consequences or special case procedures. This technique is also useful for dealing with idle degrees-of-freedom automatically.
Dynamics of a Flexible Closed-Chain Manipulator
Authors: Giovagnoni Marco 
Published: March 2021

Abstract
An approach to flexible linkage analysis is presented Requirements are defined for a correct definition of the rigid-link reference mechanism, from which small displacements are measured. The equations of motion are obtained applying the principle of virtual work. Some terms in both the real and the virtual components are neglected according to the small displacement assumption. A numerical example is presented: a flexible 3 d.o.f. manipulator is considered, the input-torque vector is defined, and the proposed approach is applied to simulate the system response.
Linearization and Jacobian Evaluation of the Dynamics of Closed-Chain Mechanical Systems
Authors: Lin Tsung-Chieh , Yae K. Harold 
Published: March 2021

Abstract
This paper presents an analytical/numerical method for linearizing the equations of motion and evaluating the system Jacobian matrices of mechanical systems with closed chains. The linearization algorithm developed here first identifies and linearizes basic recursive kinematic relationships and then applies the chain rule to the derivation of the equations of motion under the framework of recursive formulation. This method can be incorporated into formulating recursive equations of motion for general multibody dynamic systems, to handle large scale systems. Since no numerical differentiation is used in the proposed algorithm, its accuracy is comparable to symbolic, closed-form linearization. Moreover, without the need of repetitious computation to select proper perturbation quantities, this method is computationally more efficient than the finite difference method.
Dynamic Models of Robots With Linkage Structures
Authors: Wang Shin-Liang 
Published: March 2021

Abstract
A systematic approach to formulate the dynamic model of a robot with a linkage structure is presented. A dynamic model similar to that of a serial link robot can be obtained with respect to active joints only. The kinetic energy can be formulated from the Newton-Euler equation, and passive joint rates can be eliminated using loop closure equations. Inertial terms can be derived from the kinetic energy; gravitational terms from the potential energy and Lagrangian equation; and the Coriolis and centrifugal terms from the inertial terms and the Lagrangian method. This approach is very efficient for simple mechanisms, most likely to be used in linkage robots.
Attitude Control Methods for Walking Machines
Authors: Gonzalez de Santos Pablo , Nagy Peter V. , Whittaker William L. 
Published: March 2021

Abstract
In this paper four different methods for body attitude control are evaluated for their effectiveness. One of them uses all axes to level the body. The other three utilize only the vertical axes. The difference among these methods is the amount of geometric information used to calculate the intended motion and resultant differences in the motion of the machine when applying these methods. Simulations and experiments on the AMBLER walking machine were used to evaluate these differences. The all-axes attitude control method considers complete geometry thereby avoiding foot slippage, but this is at the cost of higher energy expenditure to servo three motions per leg.
On the Analysis and Optimization of a Basic Variable-Ratio Drive: The Paper Cutter
Authors: Freudenstein Ferdinand , Chen Hong Jen 
Published: March 2021

Abstract
A mechanical analysis has been developed for the forces generated in paper cutting as a function of blade geometry. This in turn permits the optimization of cutter geometry for various design objectives and provides insight into the subtleties of what might at first appear to be one of the simplest mechanisms of mankind.
Dynamics of Open and Closed Chain Spherical Mechanisms Using Quaternion Coordinates
Authors: Dooley J. R. , McCarthy J. M. 
Published: March 2021

Abstract
This paper presents a general technique for deriving the equations of motion for any open or closed chain spherical mechanism. The technique uses quaternion coordinates to represent the position of each rigid body in the mechanism. Thus, if there are n moving bodies in the chain, there are 4n generalized coordinates in the equations of motion. The use of quaternion coordinates results in standardized quadratic constraint relations representing the hinged connections between bodies in the mechanism. These constraint equations augment the equations of motion. This technique has two important features. First, it is specifically adapted to spherical mechanisms and presents all positions as rotations. Second, the quadratic form of the constraint equations simplifies the computation of velocities and accelerations compatible with the constraints. As an example the equations of motion for a closed six bar spherical chain are derived.
Topological Characteristics and Automatic Generation of Structural Synthesis of Spatial Mechanisms: Part I — Topological Characteristics of Mechanical Networks
Authors: Yang Ting-Li , Yao Fang-Hua 
Published: March 2021

Abstract
This paper presents a new viewpoint about structural composition of spatial kinematic chains; single-opened chains are regarded as basic structural units of mechanisms. The constraint characteristics (the constraint factors, Δj) of single-opened chains and the constraint characteristics (the coupled degree, κ and the κ-algorithm) of mechanical networks are presented. Thus a kinematic chain with ν independent loops is regarded to be composed of one basic link and ν single-opened chains in regular sequence.
The above mentioned topological characteristics are used for setting up a new unified model for structural analysis and synthesis, kinematics and dynamics of spatial mechanisms.
Topological Characteristics and Automatic Generation of Structural Synthesis of Spatial Mechanisms: Part II — Automatic Generation of Structural Types of Kinematic Chains
Authors: Yang Ting-Li , Yao Fang-Hua 
Published: March 2021

Abstract
Based on the single-opened chain constraints and the network topological characteristics of mechanisms, a powerful new method for structural synthesis of spatial kinematic chain with plane and nonplane linear graphs has been developed. This permits the development of a highly efficient and completely automatic program for the computer-generated enumeration of structural types of mechanisms. The method is illustrated by applying to the case of kinematic chains with up to six independent loops on a personal computer.
On the Nomenclature and Classification of Compliant Mechanisms: Abstractions of Mechanisms and Mechanism Synthesis Problems
Authors: Midha Ashok , Norton Tony W. , Howell Larry L. 
Published: March 2021

Abstract
A compliant mechanism is one which gains all or part of its mobility from the relative flexibility of its members rather than from rigid-body joints only. Compliant mechanisms offer clear advantages, such as need for fewer parts, less wear, noise and backlash due to clearances, when compared to rigid-body mechanisms performing similar functions. This important field is expected to undergo significant growth as materials with superior properties are developed. In the development of compliant mechanisms, the establishment of nomenclature and classification is of primary importance. This paper discusses common representations, i.e. names and diagrams, for a compliant mechanism. Names and diagrams will be shown to be similar because they represent “abstractions” of the same mechanism. The concept of “levels of abstraction” is introduced, and common levels of abstraction are identified. The relevance of this concept to the naming of mechanisms is shown by applying it to both rigid-body and compliant mechanism examples. Nomenclature is proposed for several of the common levels of abstraction, and issues involved in naming mechanisms are discussed. Finally, a discussion of synthesis types is presented, as are the advantages, disadvantages, and issues involved in the synthesis of a compliant mechanism.
The Transmissivity and Manipulability of Spatial Mechanisms
Authors: Tsai Ming J. , Lee Hong W. 
Published: March 2021

Abstract
A method of evaluating the transmission performance for spatial mechanisms is developed using the reciprocity of screws. The actual transmission performance of a spatial mechanism should be composed of two parts: the ability of the output that can be effectively generated by the mechanism is called the “transmissivity,” and the ability of the input that can be effectively absorbed into the rest part of the mechanism is called the “manipulability.” A more generalized index for the total transmission performance of spatial mechanisms is then defined and illustrated by some spatial four-link mechanisms.
Dynamic Characteristics for a Planar Two-Link Flexible Multibody System Including the Gravity Effects
Authors: Wiens G. J. , Tsai H. 
Published: March 2021

Abstract
This paper addresses modeling issues that arise in the formulation of the equations of motion for the flexible multibody mechanical systems intended for space applications and designed according to ground test results. A planar multibody system consisting of two flexible links interconnected by two revolute joints and a payload at its free end is proposed for the investigations. In addition to the gravity and transverse deflections (most common two conditions adopted for the research in this field), the foreshortening effects, the axial deflections and the work done by the system’s own weight on the elastic deflections are also taken into consideration. Since the slender link assumption is made, the Euler-Bernoulli Beam theory is considered sufficient and satisfactory for describing the behavior of the deformed link components. The Lagrangian formulation in conjunction with assumed displacement field method is then implemented to develop the equations of motion for the system. After achieving the analytical model for the system, a linearization about various system configurations transforms the fully coupled nonlinear differential equations into standard eigenvalue problems. In doing so, the roles played by gravity, foreshortening and system’s own weight (‘weight-load’) on the dynamic behavior of the system undergoing ground testing are examined. For analysis, the fundamental frequency of the system is chosen as a measurement index. Finally, parametric studies focusing on the mass properties of payload, lower and upper links, and actuators are undertaken to address the stability problems. Results indicate that the ‘weight-load’ exhibits interesting effects on the ‘foreshortening and stability’, hence, merits further investigation.
A New Analytical Approach for the Determination of the Transient Response in Elastic Mechanisms
Authors: Xu T. , Lowen G. G. 
Published: March 2021

Abstract
Recent work on multi-regime per cycle machinery has shown that for such systems the transient response of the link deflections, which is governed by the homogeneous solution to a Hill-type differential equation, cannot be neglected in a meaningful simulation. Based on mathematical work by E.T. Whittaker, a new analytical approach for obtaining such transient responses is given. It is achieved by the determination of the characteristic exponent in the stable regions of the Floquet solution to the Hill’s equation involved. This technique is applied to a specific elastic mechanism. Several sample computations show that the transient response may vary from near-periodic to totally aperiodic.
Efficiency of Methods for Kinematic Analysis Using the Algebra of Rotations
Authors: Fenton R. G. , Xi F. 
Published: March 2021

Abstract
The algebra of rotations is an alternative method for describing rigid body rotations. It can be efficiently used in the kinematic analysis of robots. One of the basic problems of the algebra of rotations is to determine the resultant sum of a number of sequential joint rotations. For this calculation, four new methods, in addition to the two methods already available in the literature, are proposed in this paper. The six methods are then compared analytically and numerically on the basis of the computational efficiency. The limitations to each of the methods are also discussed. It is found that the equivalent Rodrigues parameter method is the most efficient. However, the equivalent Euler parameter method is the preferred method for use since it is infinity free, initial vector independent and reasonably efficient.
On the Use of the Canonical Equations of Motion for the Dynamic Analysis of Constrained Multibody Systems
Authors: Bayo E. , Jimenez J. M. 
Published: March 2021

Abstract
We investigate in this paper the different approaches that can be derived from the use of the Hamiltonian or canonical equations of motion for constrained mechanical systems with the intention of responding to the question of whether the use of these equations leads to more efficient and stable numerical algorithms than those coming from acceleration based formalisms. In this process, we propose a new penalty based canonical description of the equations of motion of constrained mechanical systems. This technique leads to a reduced set of first order ordinary differential equations in terms of the canonical variables with no Lagrange’s multipliers involved in the equations. This method shows a clear advantage over the previously proposed acceleration based formulation, in terms of numerical efficiency. In addition, we examine the use of the canonical equations based on independent coordinates, and conclude that in this second case the use of the acceleration based formulation is more advantageous than the canonical counterpart.
Mass Flow and Derivative Moment of Inertia Flow in Planar (Geared) Linkages
Authors: Ye Zhonghe , Smith M. R. 
Published: March 2021

Abstract
The paper describes a method for the determination of the conditions for the complete shaking force and shaking moment balancing of planar linkages, including geared linkages, with revolute and prismatic joints. The conditions may be written down without the need for any kinematic analysis of the linkage by the application of two new concepts. These are the concept of mass flow for complete shaking force balance and the concept of derivative moment of inertia flow for complete shaking moment balance, the second of which is described here for the first time. A number of examples demonstrate the power of the method.
Design of an Epicyclic Transmission for Speed Control of a Turbine-Generator System
Authors: Barman Indranil , Flugrad Donald R. 
Published: March 2021

Abstract
An improved speed control method is proposed for a turbine-generator system. Whereas the present method employs a steam valve to control the flow of steam according to the desired output, the proposed system uses an epicyclic gear train to provide fine control of the speed, while coarse control is still maintained through the steam valve. The systematic design of such a gear train is the objective of this project. Two configurations are considered as suitable candidates. After the transmissions are analyzed to obtain the speed and torque relations, the dynamic equations of motion and control equations for the systems are derived for simulation purposes. The simulations are then conducted for various load cases and parameter values to determine a suitable design for application in the power industry. The final configuration allows constant generator output speeds to be reliably maintained in the face of significant load disturbances.