bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Design of a Six-Bar Linkage for an Anthropomorphic Three-Jointed Finger Mechanism
Authors: Zhang Jichuan , Guo Gongliang , Gruver William A. 
Published: March 2021

Abstract
We treat the design of a three-jointed, anthropomorphic, finger mechanism for prostheses and robotic end-effectors. Based on the study of configurations for the human finger, we propose a six-bar linkage with one degree of freedom for the finger mechanism. A model of the fingertip displacement of the mechanism is derived by a vector analysis approach. We study the effects of joint friction on the transmission efficiency. By measuring the joint positions of a human finger, we develop a mathematical model of the pinching and holding configurations for the human finger. Optimal parameters for the finger mechanism are obtained by nonlinear programming based on motion posture, locus, transmission efficiency, and weight subject to geometric and bionic constraints. Simulations indicate that the mechanism is useful in a variety of prosthetic and robotic devices.
Structural Instabilities in Platform-Type Parallel Manipulators due to Singular Configurations
Authors: Shi X. , Fenton R. G. 
Published: March 2021

Abstract
In this paper, a new method for identifying singular configurations causing instabilities in a platform-type parallel manipulator is presented. The method is based on a recently developed forward instantaneous kinematic formulation and the principle of reciprocity of screws. An analytical singularity condition is derived for a Stewart Platform type manipulator by using the method. It is believed that this is the first analytical expression for configuration singularity of a platform-type parallel manipulator. An illustrative example of a 3 DOF parallel manipulator is also discussed in detail in the paper.
The Health Management of Machines, Mechanisms, and Robots Featuring Macroscopically Smart Composite Materials With Embedded Fiber Optic Sensors
Authors: Hansknecht B. P. , Thompson B. S. , Gandhi M. V. , Foiles C. 
Published: March 2021

Abstract
The embryonic discipline of macroscopically smart materials featuring polymeric fiberous composite laminates with embedded optical fibers provides significant technological advantages if they are incorporated in the next generation of the machines, mechanisms, and robotic systems. These technological advantages can be exploited during the manufacture, the service life, and the failure prediction phases of the part life-cycle. The embedded optical fibers permit the manufacture of the part to be optimized during autoclave processing, for example, by controlling the state of cure and temperature using a new generation of manufacturing techniques involving closed-loop control algorithms. Subsequently, the optical fibers permit the vibrational response, stresses, strains, and deflections to be continuously monitored during the service of the mechanical system, and where appropriate, embedded actuator materials can be activated to develop a more desirable response as part of a health management philosophy. Finally, the optical sensing system enables the failure of the part to be predicted, because the propagation of a crack through the structure will result in the fracturing of the embedded optical fibers, and hence, the severing of the optical light paths which can be detected by this class of photonic system. This paper introduces this potentially powerful health management philosophy to the field of mechanism design by presenting for the first time experimental results from an investigation of the dynamic response of a slider-crank mechanism with a smart graphite-epoxy laminated connecting-rod featuring a polarimetric fiber optic sensor. This investigation examines one facet of this new philosophy; namely, a health monitoring activity in which the vibrational response of a flexible machine element is monitored using a fiber optic sensor.
Characterization of Robotic Operations for Dual-Arm Robots With Cooperating Manipulators
Authors: Cox Daniel J. , Tesar Delbert 
Published: March 2021

Abstract
Cooperating manipulators in dual-arm robots usually result in a mechanically overconstrained system having more actuator resources than freedom of motion, or an excess of actuator inputs. This redundancy in drivability condition provides the opportunity for choice, or decision, the fundamental quality of an intelligent machine. There are in general an infinite number of selections for actuator inputs and resultant internal load states to satisfy a specified output load state and motion trajectory in a dual-arm robot with cooperating manipulators. A geometric operation descriptor provides the fundamental geometric relationships for motion and constraint in cooperative dual-arm robotic operations. Cooperative modes of operation for dual-arm robots are characterized using the geometric operation descriptor to provide a basis of solution to the redundancy in drivability of the system. Modes of operation involving single objects as well as two-object operations are described for the dual-arm robot with cooperating manipulators.
Optimization of the Robot Calibration Process
Authors: Zak G. , Fenton R. G. , Benhabib B. 
Published: March 2021

Abstract
Most industrial robots cannot be off-line programmed to carry out a task accurately, unless their kinematic model is suitably corrected through a calibration procedure. However, proper calibration is an expensive and time-consuming procedure due to the highly accurate measurement equipment required and due to the significant amount of data that must be collected. To improve the efficiency of robot calibration, an optimization procedure is proposed in this paper.
The objective of minimizing the cost of the calibration is combined with the objective of minimizing the residual error after calibration in one multiple-objective optimization. Prediction of the residual error for a given calibration process presents the main difficulty for implementing the optimization. It is proposed that the residual error is expressed as a polynomial function. This function is obtained as a result of fitting a response surface to either experimental or simulated sample estimates of the residual error. The optimization problem is then solved by identifying a reduced set of possible solutions, thus greatly simplifying the decision maker’s choice of an effective calibration procedure. An application example of this method is also included.
Unique Joint Displacement Generation for Redundant Robotic Systems
Authors: Chung Y. S. , Griffis M. , Duffy Joseph 
Published: March 2021

Abstract
This paper presents a novel, practical, and theoretically sound kinematic control strategy for redundant serial manipulators. This strategy yields repeatability in the joint space of a redundant serial manipulator whose end effector undergoes some general cyclic type motion. This is accomplish by defining a potential energy function that is based on springs being theoretically or conceptually located in the joints of the manipulator (torsional springs for revolute joints, translational springs for prismatic joints).
Previous researchers have also minimized potential energy functions to solve the inverse kinematic problem for redundant serial manipulators. However, to the authors’ knowledge, the new strategy is the first to include the free angles of torsional springs and the free lengths of translational springs. This is important because it provides a meaningful reference for zero potential energy i.e. when all joints are at their free angles or free lengths. This reference for zero potential energy ensures the repeatability in the joint space of a redundant serial manipulator whose end effector undergoes a cyclic-type motion.
Choices for the free angle and torsional stiffness of a joint (or the free length and translational stiffness) are made based upon the mechanical limits of the joint. For instance, the free angle of a joint is that angle which is midway between joint limits. Joint stiffnesses are chosen so that the most dexterous joint is the most pliable, and so that the least dexterous joint is the stiffest. This strategy ensures that joints of the manipulator are kept away from their respective joint limits.
A Generalized Performance Sensitivity Synthesis Methodology for Four-Bar Mechanisms
Authors: Lee Ming-Yih , Erdman Arthur G. , Faik Salaheddine 
Published: March 2021

Abstract
A generalized accuracy performance synthesis methodology for planar closed chain mechanisms is proposed. The relationship between the sensitivity to variations of link lengths and the location of the moving pivots of four-link mechanisms is investigated for the particular objective of three and four position synthesis. In the three design positions case, sensitivity maps with isosensitivity curves plotted in the design solution space allow the designer to synthesize a planar mechanism with desired sensitivity value or to optimize sensitivity from a set of acceptable design solutions. In the case of four design positions, segments of the Burmester design curves that exhibit specified sensitivity to link length tolerance are identified. A performance sensitivity criterion is used as a convenient and a useful way of discriminating between many possible solutions to a given synthesis problem.
The Anatomy of Smart Materials and Structures, and Their Influence on Design Practices for Mechanisms, Machines and Robotic Systems
Authors: Thompson B. S. , Gandhi M. V. , Choi S. B. 
Published: March 2021

Abstract
This paper presents an exposition on the embryonic eclectic field of smart materials and structures, prior to discussing how this class of biomimetic materials will influence design practices in the field of machines, mechanisms and robotic systems. The development of smart structures typically involves the macroscopic synthesis of materials with both functional and structural properties by exploiting biomimetic philosophies. The most innovative class of these macroscopically adaptive materials typically feature combinations of actuators, sensors, and microprocessing capabilities which enable them to actively change their mass, stiffness and energy-dissipation characteristics in real-time. Such capabilities are particularly relevant to the design of mechanisms, machines and robots that must operate under variable service conditions and in unstructured environments.
Geometric Conditions for the Satisfaction of Order in Four Position Synthesis of Four-Bar Linkages
Authors: Mirth John A. 
Published: March 2021

Abstract
A mechanism that cannot pass through all precision positions in the correct sequence is said to violate the order condition. This paper establishes the order requirements for the precision position synthesis of all Grashof and non-Grashof four-bar linkages. These order requirements are based on three geometric characteristics of the four-bar mechanism: the angle of one of the rotating links that is attached to the ground link; the limits that the entire mechanism imposes on this rotating link; and the dyad configurations for the dyad that is opposite the ground pivot of this link. The results improve upon traditional discussions of the order problem by including all four-bar linkages, rather than just those of a specified Grashof type. A table summarizes the results in a form that allows for their implementation into computer programs for linkage design and analysis.
A New Parameter for Transmission Quality and Output Sensitivity Analysis of Mechanisms
Authors: Wu Fubang , Lankarani H. M. 
Published: March 2021

Abstract
A Transmission Merit Parameter (TMP) is defined in this paper which comprehensively reflects the transmission quality and output sensitivity of a mechanism to its dimensional disturbance. The TMP is derived from direct differentiation of the independent relationships among the coordinates in the form of the determinant of the constrain Jacobian matrix. It is shown that the idea of TMP is the extension of conventional transmission angle and without a measure such as TMP, representation of the transmission quality for complex mechanisms would be a difficult task.
Rectified Synthesis of Coupler-Driven Four-Bar Mechanisms for Four-Position Motion Generation
Authors: Bawab S. , Kinzel Gary L. , Waldron Kenneth J. 
Published: March 2021

Abstract
A rectified synthesis procedure for designing coupler-driven four-bar mechanisms to pass a moving lamina through four precision positions is developed. The procedure includes the elimination of circuit, branch and order defects. This is achieved with the aid of Roberts’ linkage. The procedure has been implemented in the interactive synthesis package RECSYN.
Machine Design Projects Using TK Solver
Authors: Goatley Mike , Echempati Raghu 
Published: March 2021

Abstract
In a machine design course, working on design projects is essential to learning how to apply the material. However, the hand calculations are often long or require the use of a computer to supply more information than possible through hand calculations alone, especially for repetitious iterations. TK Solver, by Universal Technical Systems, Inc. makes these iterations quick and easy compared to other available software. TK Solver has been used to make the large number of calculations needed, in the design of machine elements for example, to select bearings from a catalog knowing the required life and load rating. Also, in the design of gears and pinions, many trials of running through the same set of equations while only changing the diametral pitch and face width are needed to completely specify the dimensions, of the component while falling within the necessary safety factor criterion. Once these equations are set up, the necessary variables can be changed to accommodate any type of bearing load or gear combination.
An Automated Inversion Apporach to Closed-Form Kinematic Analysis of Planar Mechanisms
Authors: Biswas Arunava , Kinzel Gary L. 
Published: March 2021

Abstract
In this paper an inversion approach is developed for the analysis of planar mechanisms using closed-form equations. The vector loop equation approach is used, and the occurrence matrices of the variables in the position equations are obtained. After the loop equations are formed, dependency checking of the unknowns is performed to determine if it is possible to solve for any two equations in two unknowns. For the cases where the closed-form solutions cannot be implemented directly, possible inversions of the mechanism are studied. If the vector loop equations for an inversion can be solved in closed-form, they are identified and solved, and the solutions are transformed back to the original linkage. The method developed in this paper eliminates the uncertainties involved, and the large number of computations required in solving the equations by iterative methods.
Circuit Rectification for Four Precision Position Synthesis of Stephenson Six-Bar Linkages
Authors: Mirth John A. , Chase Thomas R. 
Published: March 2021

Abstract
Circuit rectification ensures that a linkage may reach all precision positions without disassembly. The circuit characteristics of Stephenson six-bar linkages can be established by examining the interaction of the four-bar and five-bar chains within the linkage. Preliminary synthesis of the four-bar chain introduces specific conditions that must be met by the five-bar chain for all of the precision positions to lie on a single circuit. These conditions are based on the relationship between the four-bar coupler curve and the dyads/triads that are generated from the centerpoint curve of the final synthesis step. The travel of the coupler curve between the precision positions is compared with the reach of the final dyad/triad to establish circuit conditions. The circuit conditions are applied to points along the centerpoint curve of the final synthesis step to identify those curve segments which will produce a mechanism with all precision positions on the same circuit.
Kinematic and Static Force Analysis of Rocker-Pin Jointed Silent Chains With Involute Sprockets
Authors: Bucknor N. K. , Freudenstein Ferdinand 
Published: March 2021

Abstract
A quasi-static model has been developed for a silent (inverted-tooth) chain drive featuring a rocker-pin-jointed chain and sprockets with involute teeth. The model incorporates the effects of clearances in the rocker-pin joints and the geometry of link/sprocket engagement. The influence of various model parameters on the chain drive torque-ratio is examined, a primary point of interest being the fluctuations in the torque-ratio due to chordal action. In some cases, the torque-ratio variation is found to be less than that for the equivalent pin-jointed chain drives. Additionally, the center distances corresponding to the maximum and minimum torque variation are not fixed, as in the case of a pin-jointed chain. An optimization method is used as an aid in determining the governing geometric constraints since multiple joint configurations can be selected, given the clearances introduced by the rocker-pin joints. The resulting system of equations is fully constrained for a physically consistent chain configuration.
The Second Order Optimum Synthesis of a Compound Mechanism With Flexible Member
Authors: Meng Caifang , Dai Zuo , Cha Jianzhong 
Published: March 2021

Abstract
An optimum synthesis of a compound mechanism with flexible member (CMFM) is reported in this paper. First, the concepts of the first order optimum synthesis (FOOS) and the second order optimum synthesis (SOOS) are given. Then, the SOOS for the CMFM in a complete period and a half of period are carried out based on the mathematical model established for the SOOS of the CMFM. The results of the SOOS are obtained through the IIO software, an integrated intelligent optimization software environment, and the differences between specified and generated angular velocities are analyzed.
Kinematic Analysis and Synthesis Type III Movable Spatial 6R Mechanism With Three Adjacent Parallel Axes
Authors: Lee Chung-Ching , Yan Hong-Sen 
Published: March 2021

Abstract
Based on matrix algebra, we derive the general analytical kinematic solutions of Type II movable spatial 6R mechanism with three adjacent parallel axes. This 6R mechanism was previously identified by the authors, and one of its special form is proposed as the retracting and wheel twisting mechanism for aircraft landing gears. A graphical synthesis technique by descriptive geometry is presented for the kinematic synthesis of the landing gear mechanism. A numerical example is given, and the mobility of this design is verified by computer animation of motions.
Nonlinear Optimal Design of Dynamic Mechanical Systems
Authors: Potter T. E. , Willmert K. D. , Sathyamoorthy M. 
Published: March 2021

Abstract
Mechanism path generation problems which use link deformations to improve the design lead to optimization problems involving a nonlinear sum-of-squares objective function subjected to a set of linear and nonlinear constraints. Inclusion of the deformation analysis causes the objective function evaluation to be computationally expensive. An optimization method is presented which requires relatively few objective function evaluations.
The algorithm, based on the Gauss method for unconstrained problems, is developed as an extension of the Gauss constrained technique for linear constraints and revises the Gauss nonlinearly constrained method for quadratic constraints. The derivation of the algorithm, using a Lagrange multiplier approach, is based on the Kuhn-Tucker conditions so that when the iteration process terminates, these conditions are automatically satisfied. Although the technique was developed for mechanism problems, it is applicable to any optimization problem having the form of a sum of squares objective function subjected to nonlinear constraints.
Backlash Control via Redundant Drives: An Experimental Verification
Authors: Tsai Lung-Wen , Chang Sun-Lai 
Published: March 2021

Abstract
In this paper, a novel concept for the control of backlash in geared servo-mechanisms is demonstrated with a prototype manipulator. The concept utilizes unidirectional redundant drives to assure positive coupling of gear meshes at all times and, thereby, eliminates backlash completely. To establish a proof of concept, a two-DOF prototype manipulator with three unidirectional drives is designed and tested. Dynamic model based on Lagrange’s formulation is established. A PID controller using computed torque control technique is developed. Two experiments, one with redundant drives and the other without redundant drives, are conducted. The experimental results demonstrate that use of unidirectional redundant drives improves the repeatability of a manipulator by an order of magnitude.
Steady-State Responses of an RSRC-Type Spatial Flexible Linkages
Authors: Chang R. Y. , Sung C. K. 
Published: March 2021

Abstract
This paper presents an analytical and experimental investigation on the steady-state responses of an RSRC-type spatial flexible linkage. The kinematic analysis of the spatial rigid-body motion is performed using kinematic constraint equations to yield linear and angular positions, velocities and accelerations of the linkage. A mixed variational principle is, then, employed to derive the equations of motion governing the longitudinal, transversal and torsional vibrations of the flexible link and the associated boundary conditions. Based on these equations, the steady-state responses are predicted. Finally, an RSRC-type four-bar spatial flexible linkage is constructed and the experimental study is performed to examine the predictive capability proposed in this investigation. Favorable comparisons between the analytical and experimental results are obtained.
An Efficient Manipulator Dynamics Formulation Based Upon Newton-Euler Equations and the ZRP Method
Authors: Cheng Harry Hui , Gupta Krishna C. 
Published: March 2021

Abstract
This paper presents a formulation of robot manipulator inverse dynamics based upon the Newton-Euler equations and the zero reference position method. The angular velocities and accelerations, linear accelerations of the mass centers, and inertia forces and moments of each link of the manipulator are computed recursively starting from the base to the end-effector. But, the joint reaction forces and moments, and joint actuator forces or torques are computed recursively from the end-effector to the base. The formulation is at first carried out in the current position and then reformulated by directly utilizing the zero reference position data. The former formulation is intuitively simple; while the latter is computationally more efficient. A parametric study is also conducted to compare the relative efficiency of this formulation with the previously available formulation.
Jacobian and Stiffness Analysis of a Novel Class of Six-DOF Parallel Minimanipulators
Authors: Tahmasebi Farhad , Tsai Lung-Wen 
Published: March 2021

Abstract
The Jacobian and stiffness matrices of two types of novel, six-DOF parallel minimanipulators are derived. A minimanipulator consists of three inextensible limbs, each of which is driven by a two-DOF driver. Bilinear stepper motors are used as drivers in the first type minimanipulator, whereas five-bar linkages are used as drivers in the second type minimanipulator. All of the minimanipulator actuators are base-mounted. Inextensible limbs (and five-bar linkage drivers in the second type minimanipulator) improve positional resolution and stiffness of the minimanipulators in certain directions. It is shown that, at the central configuration, the stiffness matrix of the first type minimanipulator can be diagonalized (decoupled). It is also shown that the first type minimanipulator can be designed to possess direct or torsional isotropic stiffness properties. Moreover, guidelines for designing the drivers of the second type minimanipulator are established.