Journal articles: 'Redundancy (Engineering)'

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Kanno, Yoshihiro, and Yakov Ben-Haim. "Redundancy and Robustness, or When Is Redundancy Redundant?" Journal of Structural Engineering 137, no. 9 (September 2011): 935–45. http://dx.doi.org/10.1061/(asce)st.1943-541x.0000416.

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Harada, Takashi. "Mode changes of redundantly actuated asymmetric parallel mechanism." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 3 (May 26, 2015): 454–62. http://dx.doi.org/10.1177/0954406215588479.

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A novel parallel mechanism which enlarges the workspace by singularity-free mode changes is proposed. The proposed mechanism has inherited the design of Linear DELTA, three translational degree-of-freedom and the moving plate driven by three linear actuators. In addition, the mechanism is extended by redundant actuation by four linear actuators and asymmetric design. New criterions about redundancy and singularity of redundantly actuated parallel mechanism using summation and product of determinants of minor matrices of the transposed Jacobian matrix are proposed. Redundant actuation and asymmetric design enables singularity-free mode changes with loss redundancy but maintains non-singularity, which is evaluated by the proposed criterions. Numerical simulations demonstrate the singularity-free mode changes of the proposed mechanism.

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POURDARVISH, AHMAD, and ZAHRA RAMEZANI. "COLD STANDBY REDUNDANCY ALLOCATION IN A MULTI-LEVEL SERIES SYSTEM BY MEMETIC ALGORITHM." International Journal of Reliability, Quality and Safety Engineering 20, no. 03 (June 2013): 1340007. http://dx.doi.org/10.1142/s021853931340007x.

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Reliability improvement problems have much importance in various engineering systems. Real-world engineering systems contain multiple levels. So, a redundancy allocation problem (RAP) is an efficient method to improve the reliability. Different from existing approaches that consider either hot or cold standby redundancy for a component, our approach considers a multi-level cold standby redundancy allocation problem (MLCSRAP). In other words, MLCSRAP is considered for the module and component levels, simultaneously. The units are duplicated by cold standby redundant units. An optimization solution methodology based on a customized memetic algorithm (MA) is presented for obtaining the optimal reliability of configuration multi-level series. The optimal multi-level redundancy allocation provides the improved reliability and lower life cycle cost. The proposed multi-level cold standby redundancy is compared with a multi-level active redundancy. Also, we allocate the cold standby redundancy at all levels using hierarchical genetic algorithm and compare two algorithms together. Finally, the numerical example illustrates how the theoretical results obtained in this paper can be applied.

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Wu, J., J.-S. Wang, L.-P. Wang, and T.-M. Li. "Dexterity and stiffness analysis of a three-degree-of-freedom planar parallel manipulator with actuation redundancy." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 221, no. 8 (August 1, 2007): 961–69. http://dx.doi.org/10.1243/09544062jmes456.

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The current paper deals with the dexterity and stiffness of a three-degree of freedom (DOF) planar parallel manipulator with actuation redundancy, which is a subpart of a four-DOF-hybrid machine tool. Based on the kinematics, the dexterity is analysed. The stiffness indices, which are the maximum deflection of the moving platform under the action of a unit force and the minimum eigenvalue of the stiffness matrix of the manipulator, are presented for investigating the stiffness. According to the minimum eigenvalue index, it is proved that actuation redundancy can improve the stiffness of the parallel manipulator. Moreover, the relationship between the singular configuration and the stiffness of the parallel manipulator is discussed. Compared with the corresponding non-redundant parallel manipulator without the redundant link, the redundantly actuated parallel manipulator has better dexterity and higher stiffness.

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Osterberg, Jorj O. "Necessary Redundancy in Geotechnical Engineering." Journal of Geotechnical Engineering 115, no. 11 (November 1989): 1513–31. http://dx.doi.org/10.1061/(asce)0733-9410(1989)115:11(1513).

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van den Brand, Mark, and Jan Friso Groote. "Software engineering: Redundancy is key." Science of Computer Programming 97 (January 2015): 75–81. http://dx.doi.org/10.1016/j.scico.2013.11.020.

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Gonçalves-Coelho, António, Gabriela Neştian, Miguel Cavique, and António Mourão. "Some Peculiarities of the Redundant Design Solutions." Advanced Materials Research 837 (November 2013): 49–54. http://dx.doi.org/10.4028/www.scientific.net/amr.837.49.

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In common speech, the term redundant is used to label superfluous repetitions that as a rule should be avoided. Nevertheless, redundancy is a linguistic tool that can play a remarkable role in the communication of complex thoughts in both the vernacular and the erudite talking or writing, which includes the field of engineering design. In the Axiomatic Design (AD) point of view, redundancy may increase the complexity of the design solutions (which is measured through their information content), but does not necessarily entail the breach of the ADs independence axiom. Hence, redundant solutions should not be excluded in a regular basis, since the ones that comply with the independence axiom are considered good design. According to this line of reasoning, the pertinence of redundant solutions should be assessed in the onset of the designing processes, bearing in mind the virtues of the likely higher simplicity of the non-redundant solutions. This paper deals with some basic concepts related to redundant design and it should be seen as a contribution to bring more insight on a subject that is not thoroughly reviewed in the known literature. Different forms of redundancy are considered, specifically the reliability motivated active and passive types, and the functionality-related alternative and augmentative kinds. The means to perceive intrinsic redundancy through the examination of the design equations are also provided, as well as some illustrative examples. The implicit conclusions are that redundant designs are much more usual that one can think at a first glance, and that the study of their peculiarities might deserve further attention.

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Bhattacharya, Debasis, and Soma Roychowdhury. "On constrained reliability maximization using active redundancy in coherent systems with non-overlapping subsystems." An International Journal of Optimization and Control: Theories & Applications (IJOCTA) 5, no. 1 (October 25, 2014): 33–39. http://dx.doi.org/10.11121/ijocta.01.2015.00205.

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The paper investigates a problem of constrained reliability maximization by allocating redundancy and proposes how to solve it for a broad group of complex coherent systems. Redundancy is an effective engineering tool to enhance system reliability to make a system fail-safe. Since adding redundancy increases the cost and complexity of a system design, it should be used wisely. The work considers an exact solution to the problem under resource constraints and finds optimal redundancy numbers. The proposed method can accommodate any number of constraints. Numerical examples have been included. A sensitivity analysis has been carried out to show how sensitive the optimal allocation of redundant components and the gain in system reliability are to the budget allocation.

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Sui, Tian Zhong, Zhen Tan, Lei Wang, Xiao Bin Gu, and Zhao Hui Ren. "A Method for Completeness Testing of Dimensioning in 2D Drawing." Applied Mechanics and Materials 319 (May 2013): 351–55. http://dx.doi.org/10.4028/www.scientific.net/amm.319.351.

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Dimensioning work is a considerably important link in the whole Engineering Drawing. For existing completeness testing of dimensioning, correct conclusion can not be drawn in case of multi-closed dimension. This paper mainly discusses the ways how to automatically check up the deficiency and redundancy of the dimensions. This paper presents a new and effective algorithm to test whether the dimensions are redundant or insufficient by means of the graph theory and intelligent search. The dimensions are transformed to non-directed graph, then detects whether they are redundant or insufficient by traversing adjacent matrix of the non-directed graph. The deficiency and redundancy of dimension for multi-views of engineering drawing can be corrected by this algorithm.

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Potkonjak, Veljko. "Application of redundant robots to constrained-motion tasks." Robotica 10, no. 5 (September 1992): 397–407. http://dx.doi.org/10.1017/s0263574700010602.

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SUMMARYThe problem of the constrained motion of robot end-effector is discussed. The redundant robot is considered, redundancy being added in order to improve robot working characteristics. In the phase of free motion towards the constraint the errors of basic non-redundant configuration are corrected by means of redundancy. During the constrained motion redundancy plays the role either of active or passive compliance. Between these two phases, the collision with the constraint occurs, and the impact can be absorbed by using redundancy.

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Hung, Min‐Hsiung, and Jen‐Kuei Ting. "A novel redundancy index for kinematically redundant manipulators." Journal of the Chinese Institute of Engineers 30, no. 1 (January 2007): 77–90. http://dx.doi.org/10.1080/02533839.2007.9671232.

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JAIN, MADHU, and RITU GUPTA. "REDUNDANCY ISSUES IN SOFTWARE AND HARDWARE SYSTEMS: AN OVERVIEW." International Journal of Reliability, Quality and Safety Engineering 18, no. 01 (February 2011): 61–98. http://dx.doi.org/10.1142/s0218539311004093.

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The redundancy is a widely spread technology of building computing systems that continue to operate satisfactorily in the presence of faults occurring in hardware and software components. The principle objective of applying redundancy is achieve reliability goals subject to techno-economic constraints. Due to a plenty of applications arising virtually in both industrial and military organizations especially in embedded fault tolerance systems including telecommunication, distributed computer systems, automated manufacturing systems, etc., the reliability and its dependability measures of redundant computer-based systems have become attractive features for the systems designers and production engineers. However, even with the best design of redundant computer-based systems, software and hardware failures may still occur due to many failure mechanisms leading to serious consequences such as huge economic losses, risk to human life, etc. The objective of present survey article is to discuss various key aspects, failure consequences, methodologies of redundant systems along with software and hardware redundancy techniques which have been developed at the reliability engineering level. The methodological aspects which depict the required steps to build a block diagram composed of components in different configurations as well as Markov and non-Markov state transition diagram representing the structural system has been elaborated. Furthermore, we describe the reliability of a specific redundant system and its comparison with a non redundant system to demonstrate the tractability of proposed models and its performance analysis.

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Ding, M. Z., C. J. Ong, and A. N. Poo. "Resolution of redundant manipulators via distance optimization." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 214, no. 8 (August 1, 2000): 1037–47. http://dx.doi.org/10.1243/0954406001523506.

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Redundant manipulators are useful in practice as they have freedom in addition to that needed for a specific end-effector position. This additional freedom has to be properly resolved, and such redundancy resolution problems have been actively studied over the past decade. The most common scheme for redundancy resolution is achieved at the joint velocity level and does not take into account the presence of obstacles. This work presents a new scheme for redundancy resolution based on maximizing the shortest distance to obstacles. The aim is to resolve the redundancy by reconfiguring the robot to be at the safest pose or furthest from obstacles. The proposed scheme resolves the redundancy at the joint position level and, hence, has the advantage of ensuring collision-free motion. Several numerical examples in two- and three-dimensional spaces demonstrate the effectiveness of the proposed scheme.

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Wang, Jinsong, Jun Wu, Tiemin Li, and Xinjun Liu. "Workspace and singularity analysis of a 3-DOF planar parallel manipulator with actuation redundancy." Robotica 27, no. 1 (January 2009): 51–57. http://dx.doi.org/10.1017/s0263574708004517.

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SUMMARYThis paper deals with the position workspace, orientation workspace, and singularity of a 3-degree-of-freedom (DOF) planar parallel manipulator with actuation redundancy, which is created by introducing a redundant link with active actuator to a 3-DOF nonredundant parallel manipulator. Based on the kinematic analysis, the position workspace and orientation workspace of the redundantly actuated parallel manipulator and its corresponding nonredundant parallel manipulator are analyzed, respectively. In the singularity analysis phase, the relationship between the generalized input velocity and the generalized output velocity is researched on the basis of the theory of singular value decomposition. Then a method to investigate the singularity of parallel manipulators is presented, which is used to determine the singularity of the redundantly actuated parallel manipulator. In contrast to the corresponding nonredundant parallel manipulator, the redundant one has larger orientation workspace and less singular configurations. The redundantly actuated parallel manipulator is incorporated into a 4-DOF hybrid machine tool which also includes a feed worktable to demonstrate its applicability.

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Wang, Xiaoguang, Qian Liu, Yefa Hu, Xin Cheng, Haohui Chen, and Longfei Huang. "The Redundant Design and Reliability Analysis of Magnetic Bearings Used for Aeroengine." Advances in Mechanical Engineering 6 (January 1, 2014): 157461. http://dx.doi.org/10.1155/2014/157461.

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The redundant design principle of weak coupling magnetic bearing system for aeroengine is put forward. A redundant design scheme of weak coupling magnetic bearing system is provided including radial and axial magnetic bearings and their control system. The performance of the weak coupling redundant magnetic bearing is analyzed with the finite element method and then compared with the strong coupling redundant magnetic bearing. The weak coupling redundant magnetic bearing has some advantages in both redundancy and load bearing capacity under the circumstance of either no failure or partial failure in the coils. In view of the increase in the number of electronic components in the control system, both reliability and redundancy are evaluated comprehensively. A compromise solution of 12-pole structure for the weak coupling redundant magnetic bearing is recommended.

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Huo, Liguo, and Luc Baron. "KINEMATIC INVERSION OF FUNCTIONALLY-REDUNDANT SERIAL MANIPULATORS: APPLICATION TO ARC-WELDING." Transactions of the Canadian Society for Mechanical Engineering 29, no. 4 (December 2005): 679–90. http://dx.doi.org/10.1139/tcsme-2005-0045.

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This paper introduces the concept of functional redundancy of serial manipulators, and presents a new resolution scheme to solve such redundant robotic tasks requiring less than six degrees-of-freedom. Instead of projecting the secondary task onto the null space of the Jacobian matrix in order to take advantage of the redundancy, the twist of end-effector is directly decomposes into two orthogonal subspaces where the main and secondary tasks lie, respectively. The algorithm has shown to be computationally efficient and well suited to solve functionally-redundant robotic tasks, such as arc-welding.

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Kelkinnama, Maryam. "Stochastic Comparisons Between Coherent Systems with Active Redundancies Under Proportional Hazards and Reversed Hazards Models." International Journal of Reliability, Quality and Safety Engineering 28, no. 01 (August 27, 2020): 2150007. http://dx.doi.org/10.1142/s0218539321500078.

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This paper is concerned with the problem of stochastic comparisons between the lifetimes of two coherent systems with active redundancy. For this purpose, we consider both the active redundancy at the system level and the redundancy at the component level. We assume that the original components are identically distributed and possibly dependent. It is also assumed that for each component, there are [Formula: see text] redundant components with possibly different lifetime distributions which follow the proportional hazards (reversed hazards) model. Under some conditions on the domination function of the system, we compare the lifetimes of the systems based on majorization orders between the parameter vectors of the proportionality of the component lifetimes. We also give sufficient conditions under which adding more redundant components imply the system improvement.

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Cașcaval, Petru, and Florin Leon. "Optimization Methods for Redundancy Allocation in Hybrid Structure Large Binary Systems." Mathematics 10, no. 19 (October 9, 2022): 3698. http://dx.doi.org/10.3390/math10193698.

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This paper addresses the issue of optimal redundancy allocation in hybrid structure large binary systems. Two aspects of optimization are considered: (1) maximizing the reliability of the system under the cost constraint, and (2) obtaining the necessary reliability at a minimum cost. The complex binary system considered in this work is composed of many subsystems with redundant structure. To cover most of the cases encountered in practice, the following kinds of redundancy are considered: active redundancy, passive redundancy, hybrid standby redundancy with a hot or warm reserve and possibly other cold ones, triple modular redundancy (TMR) structure with control facilities and cold spare components, static redundancy: triple modular redundancy or 5-modular redundancy (5MR), TMR/Simplex with cold standby redundancy, and TMR/Duplex with cold standby redundancy. A classic evolutionary algorithm highlights the complexity of this optimization problem. To master the complexity of this problem, two fundamentally different optimization methods are proposed: an improved evolutionary algorithm and a zero-one integer programming formulation. To speed up the search process, a lower bound is determined first. The paper highlights the difficulty of these optimization problems for large systems and, based on numerical results, shows the effectiveness of zero-one integer programming.

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Walker, I. D., and S. I. Marcus. "Subtask performance by redundancy resolution for redundant robot manipulators." IEEE Journal on Robotics and Automation 4, no. 3 (June 1988): 350–54. http://dx.doi.org/10.1109/56.795.

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HOSHIYA, Masaru, and Kinya YAMAMOTO. "Redundancy of Engineering System with Information Entropy." Doboku Gakkai Ronbunshu, no. 654 (2000): 355–66. http://dx.doi.org/10.2208/jscej.2000.654_355.

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Grillo, Sebastián Alberto, José Luis Vázquez Noguera, Julio César Mello Mello Román, Miguel García-Torres, Jacques Facon, Diego P. Pinto-Roa, Luis Salgueiro Salgueiro Romero, Francisco Gómez-Vela, Laura Raquel Bareiro Paniagua, and Deysi Natalia Leguizamon Correa. "Redundancy Is Not Necessarily Detrimental in Classification Problems." Mathematics 9, no. 22 (November 15, 2021): 2899. http://dx.doi.org/10.3390/math9222899.

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In feature selection, redundancy is one of the major concerns since the removal of redundancy in data is connected with dimensionality reduction. Despite the evidence of such a connection, few works present theoretical studies regarding redundancy. In this work, we analyze the effect of redundant features on the performance of classification models. We can summarize the contribution of this work as follows: (i) develop a theoretical framework to analyze feature construction and selection, (ii) show that certain properly defined features are redundant but make the data linearly separable, and (iii) propose a formal criterion to validate feature construction methods. The results of experiments suggest that a large number of redundant features can reduce the classification error. The results imply that it is not enough to analyze features solely using criteria that measure the amount of information provided by such features.

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Maistrenko, Oleksandr, Oleksandr Karavanov, Oleksii Riman, Volodymyr Kurban, Andrii Shcherba, Ihor Volkov, Taras Kravets, and Galina Semiv. "Devising a procedure for substantiating the type and volume of redundant structural-functional elements of reconnaissance-firing systems." Eastern-European Journal of Enterprise Technologies 2, no. 3 (110) (April 30, 2021): 31–42. http://dx.doi.org/10.15587/1729-4061.2021.229031.

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This paper proposes an algorithm for substantiating the type and volume of redundant structural and functional elements of reconnaissance-firing systems, taking into consideration the operational patterns of such systems. Underlying this algorithm is the combination of survivability assessment methods and reliability assessment methods. Such an arrangement aimed to improve the efficiency of the application of these methods and reduce uncertainty in the calculations. The results from calculating an example of the application of a procedure for substantiating the type and volume of redundant structural and functional elements of reconnaissance-firing systems have been analyzed. The analysis of the results shows that the set task is fulfilled, in particular the specified probability of trouble-free functioning of a reconnaissance-firing system, with a combined type of redundancy. Moreover, it implies giving preference to passive redundancy, using active one only to critical elements – individual functional elements of the control subsystem. The advantage of a mixed type of redundancy over a passive redundancy is 28 %. In addition, it has been established that the multiplicity of redundancy, for accepted conditions, should not be lower than 2. A procedure for substantiating the type and volume of redundant structural and functional elements of reconnaissance-firing systems has been devised, taking into consideration the operational patterns of such systems. The specified procedure includes an algorithm, as well as methods for assessing survivability and methods for assessing the reliability of functioning. This procedure was tested for feasibility by considering an example of justifying the type and volume of redundant structural and functional elements of reconnaissance-firing systems that produced an adequate result. The result has been confirmed by the practical application of reconnaissance-firing systems in recent armed conflicts

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Isern, E., and J. Figueras. "IDDQ Detectable Bridges in Combinational CMOS Circuits." VLSI Design 5, no. 3 (January 1, 1997): 241–52. http://dx.doi.org/10.1155/1997/93809.

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Undetectable stuck-at faults in combinational circuits are related to the existence of logic redundancy (s-redundancy). Similarly, logically equivalent nodes may cause some bridging faults to become undetectable by IDDQ testing. An efficient method for the identification and removal of such functionally equivalent nodes (f-redundant nodes) in combinational circuits is presented. OBDD graphs are used to identify the functional equivalence of candidate to f-redundancy nodes. An f-redundancy removal algorithm based on circuit transformations to improve bridging fault testability, is also proposed. The efficiency of the identification and removal of f-redundancy has been evaluated on a set of benchmark circuits.

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Ju, Jeongwoo, Heechul Jung, and Junmo Kim. "Extending Contrastive Learning to Unsupervised Redundancy Identification." Applied Sciences 12, no. 4 (February 20, 2022): 2201. http://dx.doi.org/10.3390/app12042201.

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Modern deep neural network (DNN)-based approaches have delivered great performance for computer vision tasks; however, they require a massive annotation cost due to their data-hungry nature. Hence, given a fixed budget and unlabeled examples, improving the quality of examples to be annotated is a clever step to obtain good generalization of DNN. One of key issues that could hurt the quality of examples is the presence of redundancy, in which the most examples exhibit similar visual context (e.g., same background). Redundant examples barely contribute to the performance but rather require additional annotation cost. Hence, prior to the annotation process, identifying redundancy is a key step to avoid unnecessary cost. In this work, we proved that the coreset score based on cosine similarity (cossim) is effective for identifying redundant examples. This is because the collective magnitude of the gradient over redundant examples exhibits a large value compared to the others. As a result, contrastive learning first attempts to reduce the loss of redundancy. Consequently, cossim for the redundancy set exhibited a high value (low coreset score). We first viewed the redundancy identification as the gradient magnitude. In this way, we effectively removed redundant examples from two datasets (KITTI, BDD10K), resulting in a better performance in terms of detection and semantic segmentation.

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Zhou, Xin, Yundou Xu, Jiantao Yao, Kuijing Zheng, and Yongsheng Zhao. "Stiffness modelling and comparison of the 5-UPS/PRPU parallel machine tool with its non-redundant counterpart." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 231, no. 9 (January 28, 2016): 1646–57. http://dx.doi.org/10.1177/0954405415600014.

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This article presents a derivation of the stiffness matrix of a general redundantly actuated parallel mechanism based on the overall Jacobian. The Jacobian of the constraints and actuations is derived using reciprocal screw theory. Based on the mapping relationship between constraint, actuated and external forces combined with the principle of virtual work, a compatibility equation for the deformation of all of the limbs is achieved, and the stiffness model of the general redundantly actuated parallel mechanism is derived. The 5-UPS/PRPU redundantly actuated parallel machine tool is used to illustrate this method. The parallel machine tool comprehensively reveals the effect of the elastic deformation of active–passive joints and some basic transmission parts. The stiffness model is further validated by experimental data. Moreover, the global stiffness matrix of the general redundantly actuated parallel mechanism can be separated into two parts via matrix decomposition. The first part is the stiffness matrix of the corresponding non-redundant parallel mechanism, and the second part is the stiffness matrix of the redundantly actuated limbs (actuators). The redundantly actuated 5-UPS/PRPU parallel machine tool is also investigated for further analysis. The different stiffness characteristics of the machine tool and its corresponding non-redundant 5-UPS/PRPU parallel machine tool are compared. Actuation redundancy is found to improve the stiffness performance of the machine tool efficiently.

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KHOUKHI, Amar, Luc BARON, and Marek BALAZINSKI. "A PROJECTED GRADIENT AUGMENTED LAGRANGIAN APPROACH TO MULTI-OBJECTIVE TRAJECTORY PLANNING OF REDUNDANT ROBOTS." Transactions of the Canadian Society for Mechanical Engineering 31, no. 4 (December 2007): 391–405. http://dx.doi.org/10.1139/tcsme-2007-0028.

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In this paper, a multi-objective trajectory planning system is developed for redundant manipulators. This system involves kinematic redundancy resolution, as well as robot dynamics, including actuators model. The kinematic redundancy is taken into account through a secondary criterion of joint limits avoidance. The optimization procedure is performed subject to limitations on actuator torques and workspace, while passing through imposed poses. The Augmented Lagrangian with decoupling (ALD) technique is used to solve the resulting constrained non-convex and non-linear optimal control problem. Furthermore, the final state constraint is solved using a gradient projection. Simulations on a three degrees of freedom planar redundant serial manipulator show the effectiveness of the proposed system.

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Yu, Bi Qiang, Ming Zhang, and Wen Rui Wang. "Design and Optimization of Dual-Redundancy Transmission System." Advanced Materials Research 706-708 (June 2013): 1258–61. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.1258.

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According to the special requirements of the redundant input drive system in the aerospace field, a scheme of dual-redundancy transmission system is presented and it meets the requirements that one axis can output movements no matter two input axes are working together or working alone. Based on the analysis of the scheme, structure design scheme is presented, and the matching relationship of gear teeth is derived to meet the requirement of transmission ratio. Then the multidisciplinary design optimization model of the dual-redundancy transmission system is established, in which the system is discomposed into two subsystems: differential gear train and fixed axis gear train. The multidisciplinary variable couple design optimization method of discrete variable is used in the optimal design of dual-redundancy transmission system and the optimal comprehensive scheme is obtained.

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Vieira, Hiparco Lins, João Vitor de Carvalho Fontes, and Maíra Martins da Silva. "Reliable redundancy resolution strategies for kinematically redundant parallel manipulators." Mechanism and Machine Theory 167 (January 2022): 104531. http://dx.doi.org/10.1016/j.mechmachtheory.2021.104531.

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Pueh, Lee Heow. "Global resolution of redundancy without optimization for redundant manipulators." Mechanism and Machine Theory 28, no. 1 (January 1993): 43–52. http://dx.doi.org/10.1016/0094-114x(93)90045-w.

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Saafi, Houssem, Med Amine Laribi, and Said Zeghloul. "Redundantly actuated 3-RRR spherical parallel manipulator used as a haptic device: improving dexterity and eliminating singularity." Robotica 33, no. 5 (July 9, 2014): 1113–30. http://dx.doi.org/10.1017/s0263574714001751.

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SUMMARYThis paper discusses the study of a spherical parallel manipulator (SPM) used as a haptic device for tele-operation applications. The SPM presents poor behavior in singular configurations. Redundancy is used to eliminate the parallel singularity without major changes in the mechanical structure. Comparisons in terms of kinematic and dynamic behavior between the non-redundant and redundant SPM are presented. The results prove the advantage of introducing redundancy in the actuator and sensor to improve the behavior of the SPM. A new control strategy for the redundant SPM is also proposed. The control strategy has been successfully tested and validated on a SimMechanics model.

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Lee, Aiden, and Roger Boudreau. "The effect of the number of degrees of kinematic redundancy on the actuation forces of a planar parallel manipulator." Transactions of the Canadian Society for Mechanical Engineering 42, no. 1 (March 1, 2018): 10–19. http://dx.doi.org/10.1139/tcsme-2017-0002.

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This paper proposes a two-step optimization procedure for resolving the actuation forces of a kinematically redundant planar parallel manipulator following a specified trajectory. Simulation results compare the performance of the manipulator when different degrees of kinematic redundancy are used. It is seen that the required forces are generally lower when there are more degrees of kinematic redundancy; however, more mechanical energy is required. In some cases, fewer degrees of kinematic redundancy can produce similar results from a force point of view, while requiring less energy. Furthermore, the importance of correctly choosing an initial configuration is presented. The proposed method finds an optimal initial configuration by considering a performance index along the entire trajectory. The evolution of the singularity loci as the manipulator moves along the trajectory demonstrates why certain initial configurations should not be used, even if they are optimal at the initial pose.

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Holst, Christoph-Alexander, and Volker Lohweg. "A Redundancy Metric Set within Possibility Theory for Multi-Sensor Systems." Sensors 21, no. 7 (April 3, 2021): 2508. http://dx.doi.org/10.3390/s21072508.

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In intelligent technical multi-sensor systems, information is often at least partly redundant—either by design or inherently due to the dynamic processes of the observed system. If sensors are known to be redundant, (i) information processing can be engineered to be more robust against sensor failures, (ii) failures themselves can be detected more easily, and (iii) computational costs can be reduced. This contribution proposes a metric which quantifies the degree of redundancy between sensors. It is set within the possibility theory. Information coming from sensors in technical and cyber–physical systems are often imprecise, incomplete, biased, or affected by noise. Relations between information of sensors are often only spurious. In short, sensors are not fully reliable. The proposed metric adopts the ability of possibility theory to model incompleteness and imprecision exceptionally well. The focus is on avoiding the detection of spurious redundancy. This article defines redundancy in the context of possibilistic information, specifies requirements towards a redundancy metric, details the information processing, and evaluates the metric qualitatively on information coming from three technical datasets.

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Maaroof, Omar W., Mehmet İsmet Can Dede, and Levent Aydin. "A Robot Arm Design Optimization Method by Using a Kinematic Redundancy Resolution Technique." Robotics 11, no. 1 (December 22, 2021): 1. http://dx.doi.org/10.3390/robotics11010001.

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Redundancy resolution techniques have been widely used for the control of kinematically redundant robots. In this work, one of the redundancy resolution techniques is employed in the mechanical design optimization of a robot arm. Although the robot arm is non-redundant, the proposed method modifies robot arm kinematics by adding virtual joints to make the robot arm kinematically redundant. In the proposed method, a suitable objective function is selected to optimize the robot arm’s kinematic parameters by enhancing one or more performance indices. Then the robot arm’s end-effector is fixed at critical positions while the redundancy resolution algorithm moves its joints including the virtual joints because of the self-motion of a redundant robot. Hence, the optimum values of the virtual joints are determined, and the design of the robot arm is modified accordingly. An advantage of this method is the visualization of the changes in the manipulator’s structure during the optimization process. In this work, as a case study, a passive robotic arm that is used in a surgical robot system is considered and the task is defined as the determination of the optimum base location and the first link’s length. The results indicate the effectiveness of the proposed method.

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Savir, J. "Redundancy revisited." IEEE Transactions on Very Large Scale Integration (VLSI) Systems 6, no. 4 (December 1998): 620–24. http://dx.doi.org/10.1109/92.736135.

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Oda, Naoki. "Distributed Robust Motion Controller for Redundant Manipulator Using Disturbance Observer." Journal of Robotics and Mechatronics 13, no. 5 (October 20, 2001): 464–71. http://dx.doi.org/10.20965/jrm.2001.p0464.

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In this paper, a distributed controller of the motion system with redundancy is proposed by using a disturbance observer. The motion controller of a redundant manipulator must simplify calculation, including task planning of redundant motion for use of redundancy. This paper proposes a distributed solution without excess calculation by observing interactive acceleration between subtask space. Then the proposed approach does not require strict mapping of the subtask vector into the null space of the Jacobian matrix and the introduction of the variable ratio of disturbance suppression makes it possible to consider the independence of the user-defined additional task. The validity of the proposed method is confirmed by simulation.

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Ray, Asok, and Mukund Desai. "A Redundancy Management Procedure for Fault Detection and Isolation." Journal of Dynamic Systems, Measurement, and Control 108, no. 3 (September 1, 1986): 248–54. http://dx.doi.org/10.1115/1.3143774.

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This paper presents the theoretical basis of a novel redundancy management procedure developed for fault detection and isolation (FDI) in strategic processes such as spacecraft, aircraft, and nuclear plants where multiply-redundant measurements are available for individual variables. The set of redundant measurements may comprise both direct sensor outputs and analytically derived measurements. The redundancy management procedure presented in this paper is essentially independent of the fault detection strategy and measurement noise statistics, and builds upon the concept of partitioning the set of measurements into “consistent” and “inconsistent” subsets for purposes of estimation and fault isolation, respectively. The proposed procedure is suitable for real-time applications using commercially available microcomputers and its efficacy has been verified on-line in operating nuclear reactors.

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Ren, Zhigang, Guoquan Ren, and Dinhai Wu. "Deep Learning Based Feature Selection Algorithm for Small Targets Based on mRMR." Micromachines 13, no. 10 (October 18, 2022): 1765. http://dx.doi.org/10.3390/mi13101765.

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Small target features are difficult to distinguish and identify in an environment with complex backgrounds. The identification and extraction of multi-dimensional features have been realized due to the rapid development of deep learning, but there are still redundant relationships between features, reducing feature recognition accuracy. The YOLOv5 neural network is used in this paper to achieve preliminary feature extraction, and the minimum redundancy maximum relevance algorithm is used for the 512 candidate features extracted in the fully connected layer to perform de-redundancy processing on the features with high correlation, reducing the dimension of the feature set and making small target feature recognition a reality. Simultaneously, by pre-processing the image, the feature recognition of the pre-processed image can be improved. Simultaneously, by pre-processing the image, the feature recognition of the pre-processed image can significantly improve the recognition accuracy. The experimental results demonstrate that using the minimum redundancy maximum relevance algorithm can effectively reduce the feature dimension and identify small target features.

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Ni, Ming, Kai Guo Qian, Yong Gang Xie, and Zu Cheng Dai. "A Sensor Network Routing Protocol Based on Node Residual Energy." Advanced Materials Research 816-817 (September 2013): 1081–84. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.1081.

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This paper mainly discusses the problem of wireless sensor network routing protocols. The flooding routing protocol has disadvantages of hidden terminal, information implosion and emerging redundant packet copies which consume more node energy. A sensor network routing protocol based on node residual energy (RPBEN) is proposed and evaluated. The new protocol choices a small number of nodes that have maximum remaining energy as next hop routing nodes. It saves the energy by avoiding redundancy packet copies produced and improve the disadvantages of flooding routing protocol. Performance analysis and simulation experiment show that the new protocol effectively reduces the data redundancy, reduces the energy consumption and prolongs the network lifetime.

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Lu, Xiaojian, Zi’an Zeng, Xichao Lv, Xusong Luo, Gongliao Zhang, and Youping Fan. "Hybrid MMC Redundancy Configuration Calculation Method Based on Heuristic Algorithm." Journal of Physics: Conference Series 2173, no. 1 (January 1, 2022): 012077. http://dx.doi.org/10.1088/1742-6596/2173/1/012077.

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Abstract Most of the existing redundant configuration methods of modular level converters (MMC) only consider the reliability of the MMC, and rarely consider the utilization of insulated gate bipolar transistors (IGBT). A heuristic algorithm-based calculation method for hybrid MMC redundancy configuration is proposed in order to better meet the engineering practicality. Firstly, the topology of the hybrid MMC is introduced, and the correlation between submodules is introduced into the calculation of its reliability. Secondly, the index of IGBT utilization is proposed to judge the economic advantage. The effects of correlation and service life on the reliability of the hybrid MMC and the IGBT utilization are analyzed. Then, heuristic factors are constructed with reliability and IGBT utilization, and the optimal redundancy configuration scheme of hybrid MMC is obtained by heuristic algorithm. Finally, based on the parameters of Kunliulong multi-terminal hybrid DC transmission project, the calculation is verified in Matlab and compared with the results of the difference method to illustrate the feasibility and superiority of the proposed redundancy configuration calculation method.

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Hong, Weiwei, Jinxi Chen, Bingliang Ye, and Rongjiang Cui. "Innovative design method for planar mechanism configuration based on component similarity discrimination." Mechanical Sciences 13, no. 1 (April 13, 2022): 353–59. http://dx.doi.org/10.5194/ms-13-353-2022.

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Abstract. Obtaining new models of mechanical equipment to conduct mechanical innovative design through kinematic chain configuration synthesis is an effective method. However, in practice, due to the existence of similar components, existing innovative design methods easily produce redundant design schemes, which require extensive isomorphic discrimination operations, and the design process is complex. In view of existing problems, this study analyzes a method for discriminating between similar components of mechanisms from the perspective of graph theory and then applies it to the specialization of topological graphs to solve the problem of redundant design schemes. Finally, using the innovation of a drilling rig drilling arm mechanism as an example, 52 feasible schemes without redundancy are obtained. This paper provides a reference for the innovation of the configuration of planar mechanisms without design redundancy.

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Stenseng, Arne. "Cracks and Structural Redundancy." Marine Technology and SNAME News 33, no. 04 (October 1, 1996): 290–98. http://dx.doi.org/10.5957/mt1.1996.33.4.290.

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This paper proposes a way to use finite element models to determine the effect of fatigue cracks in ship structures. Cracks of different lengths are modeled and the maximum nodal stress at the crack tip is used to estimate the stress intensity level. The calculated stress intensity factor is substituted into fracture mechanics equations to calculate the rate of crack growth and the critical crack length. The main advantage to calculating the stress intensity factor from an appropriate finite element model is that load redistribution effects are included. Since the ship structure is redundant, load shedding and multiple load paths can significantly reduce the propagation rate and thereby improve the safety of the structure. Including the crack in the finite element model also makes it possible to study the crack's impact on the stress levels in surrounding structure. The method is independent of the cause of structural failure, hence this kind of analysis can be used to investigate the effects of cracks created by fatigue, collision, or grounding damage.

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Abouei Ardakan, Mostafa, Mohammad Sima, Ali Zeinal Hamadani, and David W. Coit. "A novel strategy for redundant components in reliability--redundancy allocation problems." IIE Transactions 48, no. 11 (August 11, 2016): 1043–57. http://dx.doi.org/10.1080/0740817x.2016.1189631.

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Hu, Lanqing, Haibo Gao, Haibo Qu, and Zhen Liu. "Closeness to singularity based on kinematics and dynamics and singularity avoidance of a planar parallel robot with kinematic redundancy." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 236, no. 7 (November 25, 2021): 3717–30. http://dx.doi.org/10.1177/09544062211045475.

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Planar parallel robots are appealing due to their structural simplicity, high stiffness, and large payload capacity. One major problem is that workspace and singularity of non-redundant parallel robots are unchangeable. Hence, when the desired path crossed with singularity or exceeded the workspace’s boundary, the robot is incapable of finishing the task. Another one is closeness to singularity. If one can know the distance between the end manipulator and singularity or workspace’s boundary, the robot will avoid lose control or breakdown. Compared with the traditional planar parallel robot, the planar parallel robot with kinematic redundancy possesses the advantages of avoiding singularity, expanding workspace by adjusting kinematic redundancy parameter. Therefore, the objective of this article is to present an offline action-strategy of a planar robot with kinematic redundancy to measure the closeness to singularity and avoid singularity. It includes two main parts: First, before the robot moves along the desired paths, the closeness to singularity was measured based on the performance of the kinematics and dynamics so that one can know where to pause the robot. Second, an algorithm is designed to previously find the proper kinematic redundancy parameters for changing singularity and workspace. Hence, the robot can smoothly move far from the singularity to finish all paths. The results indicate that the robot can adjust its configuration to well realize the goal by the offline action-strategy.

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Potkonjak, Veljko, Goran Djordjević, Čedomir Milosavljević, Dragan Antić, and Dejan Popović. "Kinematic redundancy and sensor redundancy for enhancement of robot tracking performance." Journal of Intelligent and Robotic Systems 15, no. 3 (March 1996): 263–89. http://dx.doi.org/10.1007/bf00572263.

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Pandi, Sreekrishna, Frank Gabriel, Juan A. Cabrera, Simon Wunderlich, Martin Reisslein, and Frank H. P. Fitzek. "PACE: Redundancy Engineering in RLNC for Low-Latency Communication." IEEE Access 5 (2017): 20477–93. http://dx.doi.org/10.1109/access.2017.2736879.

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Wang, Jun Wei, Ke Huang, Le Lu, Zhi Gang Fang, Xian Wang Kong, and Jian Tong Wu. "The Reliability Design and Analysis of the Control System in 29th Olympics Opening and Closing Ceremony." Advanced Materials Research 181-182 (January 2011): 565–70. http://dx.doi.org/10.4028/www.scientific.net/amr.181-182.565.

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Conventionally, partial redundancy is applied at frail or crucial parts in most control system. As for the significant occasion of the Olympics Opening and Closing Ceremony, any fault of the control system may result in immeasurable losses. In this paper, we focus on redundancy policies and introduce the realizing of two different redundancy systems: the basic whole redundancy system, and the Hetero-type whole redundancy system, viz. two different control kernels (the PLC and its corresponding software and network) used in the same system. These two redundancy control systems are implemented at examination place and the National Stadium individually. These control systems set a successful example of the redundancy system implemented in mechanical control system at important occasions. By analyzing and comparing the reliability of the two redundancy systems, we get the results that the Hetero-type whole redundancy system has higher reliability than the basic whole redundancy system.

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Hazra, Nil Kamal, and Asok K. Nanda. "Component Redundancy Versus System Redundancy in Different Stochastic Orderings." IEEE Transactions on Reliability 63, no. 2 (June 2014): 567–82. http://dx.doi.org/10.1109/tr.2014.2315917.

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Rebollo-Neira, L. "Dictionary redundancy elimination." IEE Proceedings - Vision, Image, and Signal Processing 151, no. 1 (2004): 31. http://dx.doi.org/10.1049/ip-vis:20040294.

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Luo, Xuan, Fugui Xie, and Xin-Jun Liu. "Kinematic calibration of the 3-degree-of-freedom redundantly actuated spatial parallel module of a five-axis hybrid machine." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 234, no. 9 (April 17, 2020): 1185–97. http://dx.doi.org/10.1177/0954405420911299.

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As a new type of manufacturing equipment, redundant hybrid machines have the theoretical advantage over the traditional serial machines in efficiently processing large structural parts with high material removal ratio and complex parts with curved surfaces. In order to solve the accuracy problem of the redundantly actuated spatial parallel module of a five-axis hybrid machine, an improved kinematic calibration method is proposed in this article. First, different from error modeling for the corresponding non-redundant parallel module, the geometric error model of the redundantly actuated spatial parallel module considers the deformations at active joints caused by actuation redundancy as an error source. Then, the applicable error model is developed using projection technique to remove the need of active joints’ stiffness measurement or modeling. Later, the practical error model is derived from model reduction method to avoid using additional sensors or gratings. Finally, three forms of relative measurement and step identification are adopted for the calibration work, and the bilinear interpolation compensation function is introduced to ensure the calibration effect. On this basis, the kinematic calibration of the redundantly actuated spatial parallel module is conducted. The max position errors are reduced from original −0.192 to 0.075 mm after RM1 and SI1, and then further reduced to 0.014 mm after bilinear interpolation compensation, while the max orientation errors are reduced from −0.017° and 0.249° to −0.005° and −0.007° after RM2 and SI2, and RM3 and SI3, respectively. A contrasting experiment is also carried out with the previous method for the corresponding non-redundant parallel module. As a result, the proposed method shows better convergence value and speed in identifying error parameters, and therefore the effectiveness and efficiency of the proposed method for the redundantly actuated spatial parallel module are validated.

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Wang, Hongxing, LianZheng Ge, Ruifeng Li, Yunfeng Gao, and Chuqing Cao. "Motion optimization of humanoid mobile robot with high redundancy." Assembly Automation 41, no. 2 (January 18, 2021): 155–64. http://dx.doi.org/10.1108/aa-06-2020-0083.

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Purpose An optimal solution method based on 2-norm is proposed in this study to solve the inverse kinematics multiple-solution problem caused by a high redundancy. The current research also presents a motion optimization based on the 2-Norm of high-redundant mobile humanoid robots, in which a kinematic model is designed through the entire modeling. Design/methodology/approach The current study designs a highly redundant humanoid mobile robot with a differential mobile platform. The high-redundancy mobile humanoid robot consists of three modular parts (differential driving platform with two degrees of freedom (DOF), namely, left and right arms with seven DOF, respectively) and has total of 14 DOFs. Given the high redundancy of humanoid mobile robot, a kinematic model is designed through the entire modeling and an optimal solution extraction method based on 2-norm is proposed to solve the inverse kinematics multiple solutions problem. That is, the 2-norm of the angle difference before and after rotation is used as the shortest stroke index to select the optimal solution. The optimal solution of the inverse kinematics equation in the step is obtained by solving the minimum value of the objective function of a step. Through the step-by-step cycle in the entire tracking process, the kinematic optimization of the highly redundant humanoid robot in the entire tracking process is realized. Findings Compared with the before and after motion optimizations based on the 2-norm algorithm of the robot, its motion after optimization shows minimal fluctuation, improved smoothness, limited energy consumption and short path during the entire mobile tracking and operating process. Research limitations/implications In this paper, the whole kinematics model of the highly redundant humanoid mobile robot is established and its motion is optimized based on 2-norm, which provides a theoretical basis for the follow-up research of the service robot. Practical implications In this paper, the whole kinematics model of the highly redundant humanoid mobile robot is established and its motion is optimized based on 2-norm, which provides a theoretical basis for the follow-up research of the service robot. Social implications In this paper, the whole kinematics model of the highly redundant humanoid mobile robot is established and its motion is optimized based on 2-norm, which provides a theoretical basis for the follow-up research of the service robot. Originality/value Motion optimization based on the 2-norm of a highly redundant humanoid mobile robot with the entire modeling is performed on the basis of the entire modeling. This motion optimization can make the highly redundant humanoid mobile robot’s motion path considerably short, minimize energy loss and shorten time. These researches provide a theoretical basis for the follow-up research of the service robot, including tracking and operating target, etc. Finally, the motion optimization algorithm is verified by the tracking and operating behaviors of the robot and an example.

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Journal articles on the topic 'Redundancy (Engineering)'

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