bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resolving Velocity-Degenerate Configurations (Singularities) of Redundant Manipulators
Authors: Podhorodeski Ron P. , Nokleby Scott B. , Wittchen Jonathan D. 
Published: December 2020

Abstract
A kinematically-(joint)-redundant spatial manipulator will not be velocity degenerate (singular) if any combination of six of its joints span the 6-system of general velocity. Therefore, all 6x6 sub-matrices of the matrix of joint screw coordinates J (commonly referred to as the Jacobian) must be rank deficient for a spatial joint-redundant manipulator to be velocity degenerate. Concurrency of zero 6x6 sub-matrix determinants of J allows sets of joint-displacement conditions leading to velocity-degenerate configurations to be identified. For actual manipulators, each set of degeneracy conditions must be checked to see if the conditions are feasible for existing device dimensions and occur within existing joint displacement limits. Within this work, the concept of concurrency of zero 6x6-sub-matrix determinants of J is considered and applied to the identification of velocity degeneracies for the Canadian Space Agency (CSA)/International Submarine Engineering (ISE) STEAR Testbed Manipulator (STM). The STM consists of two 7-jointed arms that are kinematically similar to the arms of the Special Purpose Dextrous Manipulator (SPDM) proposed for use on the International Space Station (ISS). Five unique 2-condition families of velocity degenerate configurations are found to cause velocity degeneracies for each of the 7-jointed arms. It is shown that only four of these five potential degeneracies correspond to reachable families of joint-displacement configurations for the CSA/ISE STM arms.
Design of Planar Miniaturized Mechanisms With Flexural Pivots
Authors: Schönherr Jürgen , Müglitz Jörg 
Published: December 2020

Abstract
The paper deals with synthesis, modeling and analysis of mechanisms with flexural pivots preferably used in micro-systems, measuring devices, or medical devices. Among other things, it will be shown that rotary joints can be replaced by flexural pivots so that the kinematic performance will be kept. Already in the phase of kinematic design, one has pay attention to material properties, load, and strain to ensure both the mobility and the strength of the mechanism. Using two examples, a Robert’s straight line generator and a trunk-like motion generating mechanism, it is shown here, how a relatively simple multi-body model can be used effectively for mechanism analysis and optimization.
Statically Balanced Compliant Mechanisms (SBCM’S): An Example and Prospects
Authors: Herder Just L. , van den Berg Fred P. A. 
Published: December 2020

Abstract
In some applications of compliant mechanisms, the fact that energy is stored in the elastic members presents a problem. For instance, in manually operated instruments, such as surgical forceps, the operating force should preferably be proportional to the gripping force, while forces introduced by the bending of elastic elements would disturb this force transmission process. To restore the force transmission quality, compliant mechanisms may be statically balanced, resulting in statically balanced compliant mechanisms (SBCM’s). This paper presents an example of a compliant surgical forceps mechanism, which is statically balanced by a low-friction rolling-link compensation mechanism. Force feedback is restored to the extent that the pulse in an artificial artery can be perceived clearly.
3-D Extension for MIT-MANUS: A Robot-Aided Neuro-Rehabilitation Workstation
Authors: Krebs Hermano I. , Buerger Stephen P. , Jugenheimer Kristin A. , Williams Dustin , Hogan Neville 
Published: December 2020

Abstract
An extension to an existing planar manipulator for robot-aided therapy is described. The MIT-MANUS rehabilitation workstation, shown to be effective in sensorimotor training of recovering stroke patients, is augmented by the addition of a module permitting movements in a 3-dimensional workspace. Key analyses in the mechanical design of the new module are described. A compact, screw-driven, low mechanical impedance module meets the target requirements. Manufacturing of this novel device will be followed shortly by its deployment in clinical trials.
Characterization of Dynamics in Special 6-6 PKMs
Authors: Shamblin Scott A. , Wiens Gloria J. 
Published: December 2020

Abstract
This paper presents a study on the contributions of the dynamics on the performance of a special 6-6 parallel kinematic mechanisms, with application to machine tools. Using Kane’s method, the dynamics equations of motion are derived with inclusion of the strut masses. Comparative observations are made using both workspace and sample trajectory based characterizations.
Improving Kinematic Characteristics of Geneva Mechanisms Using Variable Input Speed
Authors: Lee Jyh-Jone , Cho Chih-Chong , Chang Sun-Lai 
Published: December 2020

Abstract
A method is proposed to improve the kinematic characteristics of the conventional Geneva mechanism. Rather than driving the input crank at a uniform speed, suitably changing the crank speed can not only eliminate the impact loading at the beginning and end of the motion cycles but also reduce the wheel peak velocity and/or the peak acceleration values. In this paper, we investigate design criteria and formulation for the planning of such input crank motion. Examples for the input planning via the general Bezier’s curve model are then given to illustrate the procedure. With no need to alter the conventional structure, the result provides a simple and practical tool for designing an intermittent motion generating mechanism with excellent kinematic characteristics.
On the Application of Kinematic Units to the Topological Analysis of Geared Mechanisms
Authors: Liu Chia-Pin , Chen Dar-Zen 
Published: December 2020

Abstract
Based on the concept of kinematic fractionation, a systematic approach for the topological analysis of geared mechanisms is presented in this paper. It is shown that a geared kinematic chain (GKC) can be regarded as a combination of kinematic unit(s). By identifying the embedded kinematic units, kinematic insight in the GKC can be exposed. The disclosed information leads to a straightforward and promising approach to prevent inducing redundant links. This approach forms the basis of a by-inspection procedure to determine admissible assignments of the ground, input and output links in a GKC. Admissible assignments of the ground, input and output links of one degree-of-freedom 5 link GKCs are obtained as an illustrative example.
Compliant Mechanism Prototyping
Authors: Mortensen Clinton R. , Weight Brent L. , Howell Larry L. , Magleby Spencer P. 
Published: December 2020

Abstract
Flexible segments present challenges to prototyping compliant mechanisms. This paper discusses methods for prototyping compliant mechanisms, including use of 3-axis CNC milling, laser cutting, and wire EDM. Rapid prototyping methods and hybrid methods are also discussed. A method for machining living hinge prototypes with good fatigue life is also documented.
A Multi-Variable Approach to Determine the “Best” Gear Design
Authors: Houser Donald R. , Harianto Jonny , Chandrasekaran B. , Josephson John , Iyer Naresh 
Published: December 2020

Abstract
Gear design requires the designer to compromise many design variables in order to determine the best performance of a gear set. Unfortunately the designer has a multiplicity of goals including keeping both bending and pitting stresses under an allowable value, minimizing scoring, achieving minimum efficiency and trying to minimize noise. This latter response variable is rarely considered in the initial gear design. In this work, noise is considered to be one of the more important design considerations.
One approach to multi-variable gear design that has been tried is design optimization. Usually optimization techniques are limited in the number of variables that can be handled and with so many response variables, it is difficult to come up with an objective function that reflects the considerations of a real gear designer.
In this paper we present a simulation-based approach to gear design that allows the designer to essentially “run all of the cases”. The simulation accounts for the true load distribution of the gears when computing response variables. Also, such factors as manufacturing tolerances may be included in the simulation so that truly robust designs may be obtained. Rather than using an objective function approach, designs are analyzed with a dominance filter that assesses each response variable in a manner that results in the “best” design. After these “best” designs are found, an interactive viewer allows the selection of those designs that best meet the designer’s goals with regard to all design variables.
Several examples are presented in this paper. In each case, over 65,000 designs are evaluated and the dominance filter results in from 200 to 900 successful designs, depending on the tolerances that are applied. After sorting with the viewer the designer usually ends up with from 5 to 20 designs whose features may vary significantly, but have similar performances.
Theory and Programming of a Generic Gear Library
Authors: Häussler U. 
Published: December 2020

Abstract
This paper discusses an approach, which combines theoretical consideration and object oriented thoughts in order to make gear computing extentable.
A generalized calculus is investigated, which has no loss of geometrical information. Calculating the fundamental forms of the conjugated surface, the enveloped surface will have the same properties as the tool surface.
By using object oriented programming in a gear specific way, it is shown, that all programms for gear and tool design may have the same structure, and are based on the same virtual methods and classes.
The Instantaneous Friction Force for Relative Motion
Authors: Perumean Don W. 
Published: December 2020

Abstract
This paper derives the free-body diagram for involute spur gears. The principles of this derivation are applicable to any two bodies moving with relative motion having a sliding contact between them.
The derived free-body diagram shows that the equation for the instantaneous sliding friction force includes a term for the instantaneous percent sliding of the contact. This percent sliding term allows the equation for the instantaneous sliding friction force to express the influence of the exact relative motion that is taking place at the point of contact.
The instantaneous sliding friction force equation for any two bodies moving with relative motion will include a term for the instantaneous percent sliding of the contact when observed from a third reference plane considered at rest.
The derived friction force equation will require the instantaneous coefficient of sliding friction to be redefined for relative motion.
Tooth Surface Fatigue Strength of Normalized Steel Conical Involute Gears
Authors: Ohmachi Tatsuya , Iizuka Koji , Komatsubara Hidenori , Mitome Ken-ichi 
Published: December 2020

Abstract
The tooth surface fatigue strength of the conical involute gear is evaluated in this paper. Test gears are straight intersecting-axis conical gears. The material of the test gear is normalized steel. The power circulating testing machine is used in this experiment. The circulating torque is kept constant and the number of times of contact is 107. The tooth surface life is evaluated by the pitting area rate. The critical value of the circulating torque is found between 147 N·m and 157 N·m. For critical torque, the pitting area rate does not progress over 4%. The Hertzian contact stress of the test gear is calculated at the circulating torque. The contact stress should be evaluated in consideration of the wearing effects.
New Toothed Belt Matches Various Pulley-Profiles
Authors: Schaefer Frank H. 
Published: December 2020

Abstract
This paper examines the possibility of a new toothed belt construction to run in various pulley-types. The measurements from a laboratory dynamometer test stand show the belt life under special test conditions by use of HTD-, STPD- and RPP-pulleys, each with an angle of wrap of 180°. In case of locked center distance the increase of torque causes tooth climbing until belt jumping occurs. The pretension was brought into line with the torque each time the torque was increased and the jumping limit torque was determined. From literature it is expected that the results for the behavior of the HTD- and the RPP-pulley are similar. Another parameter to describe the quality of motion is the noise. Here sound power is a very effective descriptor of how noisy an object is. It was determined from sound intensity measurements for HTD- and STPD-pulleys. The ratio of the toothed belt drive used for the noise measurement was 0.63.
Full Sliding “Adhesive-Like” Contact of V-Belts
Authors: Gerbert Göran , Sorge Francesco 
Published: December 2020

Abstract
Analysis of power transmission in a belt drive consisting of e. g. two pulleys might be treated as a boundary value problem. Tight side tension FT, slack side tension FS and the wrap angle α are the three natural boundary conditions.
In the literature, theories are developed where seating and unseating as well as the power transmitting part of the contact are considered. The solutions presented so far don’t fulfil the boundary conditions properly, since a certain tension ratio FT/FS is associated with a certain contact angle and not an a priori specified one.
It appears that a new type of full sliding solution must be introduced to handle the boundary condition problem. During part of the contact there is almost no tension variation in spite of the full sliding conditions. The designation adhesive like solution is here introduced for that part. Conditions and character of the adhesive like solution are outlined in the paper.
Measurements of Forces Between a Synchronous Belt and a Pulley
Authors: Distner Martin , Johannesson Tomas 
Published: December 2020

Abstract
In modern belt profiles, power is transmitted by both normal forces and friction forces. To control the load distribution between a belt and a pulley, avoiding power circulation and local tooth load peaks, it is necessary to take into account both types of forces. An analytical model for the load distribution has previously been presented by the authors. This work also introduces the effective pitch difference, EPD, which is the actual pitch difference between a pulley and a loaded belt.
To examine these matters and verify the model, a series of 270 experiments was carried out in a two-pulley test rig. Parameters investigated are: torque, tension, belt speed, pitch difference and running time. All of the measurements were conducted under quasi-static conditions. The equipment used included a specially designed measurement pulley that can measure four different engagement forces.
Experiments show that belt speed within automotive application range has no effect on load distribution, apart from engagement and disengagement peaks. Tooth flank normal forces and land area friction forces often work against each other. Belts with dissimilar pitch difference give rise to great differences in load distributions. Even a short running time causes a redistribution of the friction forces, although their sum remains constant.
The results show that it is possible to tailor the load distribution by adjusting the EPD. This offers an opportunity to avoid power circulation and unnecessary high contact forces. Changing the EPD for the correct load distribution at each interaction is easily achieved by individual adjustment of the pulley radius.
Applications of Numerical Analysis of Hobbing to Hob Wear, Cutting Force and Gear Tooth Surface Topography
Authors: Ariura Yasutsune , Umezaki Yoji 
Published: December 2020

Abstract
A new analytical technique is developed to calculate the volume cut with every hob tooth, cutting forces and feed mark patterns. The results of calculation are compared with experimental data, resulting in their good agreements. The estimation of wear of each hob tooth, hobbing forces and errors in hobbing can be obtained by calculation using this analytical method.
Robotic Deburring of Precision Gears
Authors: Nanlawala Michael , Manesh Ali 
Published: December 2020

Abstract
Machining processes such as milling, drilling, turning, hobbing or gear teeth cutting create burrs on the edges of metal parts when the cutting tool pushes material over an edge, instead of cutting cleanly through the material. The size, shape and characteristics of the resulting burrs depend upon a number of process factors such as: tool material and its hardness, tool sharpness, tool geometry, cutting forces, ductility of the material being machined, speed and feed of the cutting tool, and depth of the cut. Except for the turning operation, a subsequent deburring operation is often required to remove the “loose” burrs and also to produce a chamfer to “break” or smooth the edges of the machined part.
Gears, in general are deburred manually or by simple mechanical equipment such as Redin™ Deburring Machine. Because of the complexity and/or specific chamfering requirements of aerospace gears, most of these gears have to be deburred manually. In general, manual deburring is a very labor intensive process. Poor quality resulting from inconsistent manual operation, health, safety and environmental related issues, and high turnover of operators incur indirect cost as well. The “Redin Deburring Machines”, however, lack the dexterity and the programmability, which are essential to meet the specific chamfering needs of usually complex shaped aerospace gears. Automating the deburring process can therefore result in significant cost reduction, improved productivity, and improved quality of deburred edges. Mainly because of these reasons, there has been industry wide demand to replace manual deburring by more efficient, reliable and safer automated deburring system.
Prediction of Automotive Gearboxes Dynamic Behavior: Part B — Numerical Simulations for the Determination of New Mechanical Design Trends
Authors: Bourdon Adeline , Yakhou Karim , Play Daniel 
Published: December 2020

Abstract
Prediction of automotive gearboxes dynamic behavior during design is made possible through the use of numerical models and virtual prototypes. But market pressures require a formalization of new mechanical design activities. The aim of the second part of these two companion papers is to exploit the results to highlight future trends in mechanical design.
Simulations performed with numerical models enable us to obtain a better understanding of the vibratory phenomena which appear in gearboxes. These models dissociate local effects, such as gear mesh phenomena, from “global” effects, due to the gearbox architecture and allow us to evaluate interactions between components. They are used for explaining some experimental observations, such as the large differences between the dynamic transmission error in “pullup position” — corresponding to an established speed or to an acceleration phase — and “pulldown position” — corresponding to a decreasing speed phase. Local gear mesh effects can not explain these large differences. They are also used for evaluating the influences of mechanical modifications to the bearing environment, on the dynamic transmission error. Then, the consequences of these results are applied to the design and optimization of new gearboxes.
New Evaluation Method on Gear Dynamics Using Continuous and Discrete Wavelet Transforms
Authors: Ohue Yuji , Yoshida Akira 
Published: December 2020

Abstract
The aim of this study is to propose a new evaluation method of gear dynamics using continuos and discrete wavelet transforms. The Wavelet Transform (WT) is a method for the time-frequency analysis of signals. In order to evaluate the difference in the gear dynamics due to the gear material, the dynamic characteristics of gear were measured using a power circulating gear testing machine. The gear dynamics were analyzed in a time-frequency domain by the continuos and discrete WTs. The new evaluation method using the WTs proposed in this paper was very useful compared with the conventional one to investigate the damping characteristic and the dynamic condition of the gear equipment.
Static and Dynamic Tooth Loading in Spur and Helical Geared Systems: Experiments and Code Validation
Authors: Baud Sébastien , Velex Philippe 
Published: December 2020

Abstract
The primary objective of this study is to validate a specific finite element code aimed at simulated dynamic tooth loading in geared rotor systems. Experiments have been conducted on a high-precision single stage spur and helical gear reducer with flexible shafts mounted on hydrostatic or hydrodynamic bearings. The numerical model is based on classical elements (shaft, lumped stiffnesses, ...) and on an original gear element which accounts for non-linear time-varying mesh stiffness, gear errors and tooth shape modifications. External and parametric excitations are derived from the instantaneous contact conditions between the mating flanks by using an iterative contact algorithm inserted in a time-step integration scheme.
In a first step, experimental and numerical results at low speeds are compared and it is demonstrated that the proposed tooth mesh interface model is valid. Comparisons are then extended to dynamic fillet stresses on both spur and helical gears between 50–6000 rpm on pinion shaft. Despite a localized problem in the case of spur gears with one particular bearing arrangement, the broad agreement between the experimental and numerical response curves proves that the model is representative of the dynamic behavior of geared systems.
Reducing Vibration on Gears by the Means of Damping Disks
Authors: Funk Wolfram , Gassner Oliver G. 
Published: December 2020

Abstract
In the past, the concepts involving secondary measures for the reduction of solid-borne noise emissions of gearings were for the most part aimed at reducing the noise emission rate of the toothed gears. Other secondary measures were not so much concerned with the gears themselves, but with other gearing components. A new approach, however, includes the use of rotating damping disks bolted to the toothed gears. The use of bolted components results in small shifts of the resonance frequencies, in nonlinear effects and finally in friction damping of vibration amplitudes due to energy dissipation. A mathematical model for calculating the damping behavior of rotating damping disks will be developed on the basis of the equations first used by Valanis [4] and will be verified by testing.
Gear Noise Diagnosis System for Automobile Transmission Using Artificial Intelligence: Improvement of Judgement Performance
Authors: Moriwaki Ichiro , Nishiyama Masahiko 
Published: December 2020

Abstract
Gear noise emitted from transmission units for automobiles should be evaluated by an expert of gear noise. Although on some production lines, quietness performance estimates from measured noise levels of the units, the estimation must be severe. There is no definite relationship between the measured noise levels and the evaluations by the experts. Therefore, for standing on the safe side, the estimation should be severe. As a result, such an automatic gear noise diagnosis system must yield transmission units with over-quality. The present study deals with a new gear noise diagnosis system to which an artificial intelligence is applied; i.e., a neural net is applied. The former evaluations by the new gear noise diagnosis system were quite good when the statistical property of the teacher signals from which the system learned was similar to that of population. This fact means many teacher signals are necessary on the practical use. The present paper describes a new method for digitizing the measured noise levels. This method provided good evaluations of the system even when the statistical property of the teacher signals were not similar to that of the population. In addition, a new method, “Moment Method” for determining the construction of the neural net was introduced instead of “Back Propagation Method”. The Moment. Method contributed to the improvement of the system judgements.