Failure recovery for wrench capability of wire-actuated parallel manipulators

Robotica ◽  
2011 ◽  
Vol 30 (6) ◽  
pp. 941-950 ◽  
Author(s):  
Leila Notash
Keyword(s):  
Failure Modes ◽  
Parallel Manipulators ◽  
Failure Recovery ◽  
Partial Recovery ◽  
Minimum Norm ◽  
Minimum Norm Solution ◽  
Actuator Failures ◽  
Force Moment ◽  
Hybrid Actuation

SUMMARYWire-actuated parallel manipulators and their failures are studied in this paper taking into consideration their failure modes. A methodology for investigating the effect of wire/actuator failures on the force/moment capability of manipulators is presented, and the criteria for full and partial recovery from these failures are established. The methodology is also applicable for the cases that the minimum norm solution for the vector of wire tensions gives a negative value for tension by treating the corresponding wire as failed. The proposed criteria are also valid for the manipulators that utilize hybrid actuation of wires and joints. Three planar wire-actuated parallel manipulators are used as the case study to illustrate the proposed methodology and criteria.

MOTION RECOVERY AFTER JOINT FAILURE IN PARALLEL MANIPULATORS

2011 ◽  
Vol 35 (4) ◽  
pp. 559-571 ◽  
Author(s):  
Leila Notash
Keyword(s):  
Failure Modes ◽  
Jacobian Matrix ◽  
Null Space ◽  
Parallel Manipulators ◽  
Point Of View ◽  
Partial Recovery ◽  
Joint Failure ◽  
Motion Recovery ◽  
Motion Performance ◽  
Planar Parallel Manipulators

In this paper, the failure of parallel manipulators is investigated. Failure modes of parallel manipulators and their causes and effects from the kinematics point of view are discussed. Methodologies for investigating the effect of failures, due to joint failure or singularity, on the motion performance of manipulators are presented, and the criteria for full and partial recovery from these failures are established. The proposed methodologies are based on the projection of the lost motion onto the orthogonal complement of the null space of the Jacobian matrix after failure. The procedure is simulated for planar parallel manipulators to examine if after joint failure the required motion of manipulator could be fully recovered; as well as to calculate the corrections to the motion of remaining joints for recovering the lost motion.

Failure Analysis Case Study of a 1.5 Meter Space Flex Harness

2017 ◽  
Author(s):  
Erick Kim ◽  
Kamjou Mansour ◽  
Gil Garteiz ◽  
Javeck Verdugo ◽  
Ryan Ross ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Field Of View ◽  
Area Of Interest ◽  
Air Stream ◽  
Novel Method ◽  
Temperature Controlled ◽  
Non Destructive ◽  
Failure Site

Abstract This paper presents the failure analysis on a 1.5m flex harness for a space flight instrument that exhibited two failure modes: global isolation resistances between all adjacent traces measured tens of milliohm and lower resistance on the order of 1 kiloohm was observed on several pins. It shows a novel method using a temperature controlled air stream while monitoring isolation resistance to identify a general area of interest of a low isolation resistance failure. The paper explains how isolation resistance measurements were taken and details the steps taken in both destructive and non-destructive analyses. In theory, infrared hotspot could have been completed along the length of the flex harness to locate the failure site. However, with a field of view of approximately 5 x 5 cm, this technique would have been time prohibitive.

Case Study and Fault Modeling for Wrong Redundancy Evaluation on DRAM Devices

2007 ◽  
Author(s):  
Martin Versen ◽  
Dorina Diaconescu ◽  
Jerome Touzel
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Fault Modeling ◽  
Mode Analysis ◽  
Root Cause ◽  
Failure Mode Analysis

Abstract The characterization of failure modes of DRAM is often straight forward if array related hard failures with specific addresses for localization are concerned. The paper presents a case study of a bitline oriented failure mode connected to a redundancy evaluation in the DRAM periphery. The failure mode analysis and fault modeling focus both on the root-cause and on the test aspects of the problem.

Methodology for Analysis of Schottky Diode Failures

2010 ◽  
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek
Keyword(s):  
Failure Mode ◽  
Schottky Diode ◽  
Failure Modes ◽  
Schottky Diodes ◽  
Failure Mechanisms ◽  
Forward Voltage ◽  
Fast Switching ◽  
Voltage Drops ◽  
The Common

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.

scholarly journals A FMEA Based Method for Analyzing and Prioritizing Performance Risk at the Conceptual Stage of Performance PSS Design

2021 ◽  
Vol 1 ◽  
pp. 81-90
Author(s):  
John Bake Sakwe ◽  
Marcus Pereira Pessoa ◽  
Sipke Hoekstra
Keyword(s):  
Failure Modes ◽  
Manufacturing Companies ◽  
Performance Risk ◽  
Performance Contracts ◽  
Product Service ◽  
Optical Sorting ◽  
Fmea Method ◽  
Performance Challenges ◽  
Product Service Systems

AbstractWith the quest for enhancing competitive position, fulfilling customer and sustainability demands, increasing profitability, asset manufacturing companies are now adapting assets towards product service systems (PSS) offered through performance contracts. Despite several benefits, the shift to performance PSS exposes industrial asset manufacturers' to performance challenges and risks. Currently, PSS designers face a challenge to exhaustively identify potential failures during PSS development. Knowledge of Product failures is critical prior to the engineering of PSS. This paper proposes a failure modes and effects analysis (FMEA) method to support designers' prioritise critical failures in performance PSS development. A case study of an optical sorting machine is used to demonstrate the method's application.

Failure mode and effect analysis (FMEA) to improve collaborative project-based learning: Case study of a Study and Research Path in mechanical engineering

2021 ◽  
pp. 030641902199904
Author(s):  
Elena Bartolomé ◽  
Paula Benítez
Keyword(s):  
Active Learning ◽  
Failure Mode ◽  
Mechanical Engineering ◽  
Failure Modes ◽  
Collaborative Study ◽  
Project Based Learning ◽  
Educational Process ◽  
Effect Analysis ◽  
Questions And Answers

Failure Mode and Effect Analysis (FMEA) is a powerful quality tool, widely used in industry, for the identification of failure modes, their effects and causes. In this work, we investigated the utility of FMEA in the education field to improve active learning processes. In our case study, the FMEA principles were adapted to assess the risk of failures in a Mechanical Engineering course on “Theory of Machines and Mechanisms” conducted through a project-based, collaborative “Study and Research Path (SRP)” methodology. The SRP is an active learning instruction format which is initiated by a generating question that leads to a sequence of derived questions and answers, and combines moments of study and inquiry. By applying the FMEA, the teaching team was able to identify the most critical failures of the process, and implement corrective actions to improve the SRP in the subsequent year. Thus, our work shows that FMEA represents a simple tool of risk assesment which can serve to identify criticality in educational process, and improve the quality of active learning.

scholarly journals A Case Study in View of Developing Predictive Models for Water Supply System Management

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3305
Author(s):  
Katarzyna Pietrucha-Urbanik ◽  
Barbara Tchórzewska-Cieślak ◽  
Mohamed Eid
Keyword(s):  
Water Supply ◽  
Predictive Models ◽  
Failure Modes ◽  
Supply System ◽  
Water Supply System ◽  
System Management ◽  
System A ◽  
Operational Failure ◽  
Operational Data

Initiated by a case study to assess the effectiveness of the modernisation actions undertaken in a water supply system, some R&D activities were conducted to construct a global predictive model, based on the available operational failure and recovery data. The available operational data, regarding the water supply system, are the pipes’ diameter, failure modes, materials, functional conditions, seasonality, and the number of failures and time-to-recover intervals. The operational data are provided by the water company responsible of the supply system. A predictive global model is proposed based on the output of the operational data statistical assessment. It should assess the expected effectiveness of decisions taken in support of the modernisation and the extension plan.

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