Failure Detection Strategy Research Articles

LIDAR-based multi-step approach for relative state and inertia parameters determination of an uncooperative target

Future Active Debris Removal missions will require an autonomous spacecraft (chaser) to safely monitor at close distance, and then approach and dispose an inactive artificial space object (target). Since these targets are uncooperative, meaning that they cannot provide any hint or help to the chaser navigation system, such operations require the target-chaser relative state and the target inertia parameters to be accurately estimated relying only on measurements from active or passive Electro-Optical sensors. In this framework, this paper proposes an original multi-step architecture for the estimation of the relative motion and inertia parameters of an uncooperative target during a close-range monitoring trajectory. In the first phase, LIDAR-based pose measurements and a smoothing approach are used to retrieve accurate, linearly independent estimates of the target angular velocity. These estimates are then used to compute the target's moments of inertia ratios solving a linear system based on the conservation equation for the angular momentum. Once the inertia parameters are accurately estimated, the LIDAR-based pose measurements are used to feed an Unscented Kalman Filter to determine the full relative state according to a loosely coupled configuration. The architecture foresees autonomous failure detection strategies to avoid divergence in the relative state estimation error caused by unavoidable, unfavorable target observation conditions occurring during the monitoring trajectory. Performance assessment is carried out through numerical simulations realistically reproducing close-range relative motion dynamics and LIDAR sensor operation, and considering targets characterized by highly variable size, shape, and orbital dynamics as test cases.

Structural Failure Detection Using Wireless Transmission Rate From Piezoelectric Energy Harvesters

This article presents a new self-powered wireless failure detection method that uses different signal transmission rates from piezoelectric energy harvesters. Reliable signal transmission from a wireless sensor network has been challenging due to the power supply issue, often covered by batteries that need regular replacement. Piezoelectric energy harvesting is an excellent option to power the sensors in a vibrational environment, but the power level is limited by input vibrational energy. In this article, we introduce a new failure detection strategy that uses multifunctional piezoelectric material for vibration sensing and energy harvesting. That is, when the vibration is stronger and the material strain is higher, piezoelectric material produces higher voltage, and power. Different power level from multiple piezoelectric sensors is used for sensing structural failure. We design a simple power management circuit that saves power proportional to the piezoelectric voltage so that the piezoelectric patch with higher strain can transmit more frequent wireless signals (higher transmission rate). To store the piezoelectric power, the circuit is composed of a full-bridge rectifier, a single pole double throw switch, a comparator with hysteresis, and a wireless transmitter (Zigbee). The failure detection performance is investigated in a case study that monitors screw joint failure in a vibrating plate. Reliability-based design optimization is conducted to determine the piezoelectric sensor network in terms of the number and sizes of multiple piezoelectric (PZT) patches. The test results show that the proposed system successfully powers the wireless transmitter using the ultra-low scale of power from the PZT sensors (microwatt) and detect the different combination of screw joint failure in the vibrating plate.

A robust tracking algorithm with on online detector and high-confidence updating strategy

The discriminative correlation filter-based tracking algorithms cannot correctly track the target if the target is occluded or out of view and reappears in the field of vision, and they cannot ensure the tracking model is updated correctly if the tracking information is not correct. In this paper, a robust correlation tracking algorithm is proposed. Here, a failure detection strategy, which is based on the maximal confidence score and peak-to-sidelobe ratio to detect or measure the reliability of the tracking result, is integrated into the tracker. Moreover, the redetection module based on the keypoints matching method for consensus voting is introduced into the proposed tracking algorithm to redetect objects in case of tracking failure. In addition, an adaptive high-confidence updating method is proposed to avoid error model information introduced into the tracker caused by occlusions, out-of-view or illumination changes, where the learning rate is determined by the change rate of the confidence map. The OTB-2015 dataset and VOT-2016 dataset are used to evaluate the performance of the proposed tracking algorithm. The experimental results show that the proposed tracking algorithm performs better than most of the state-of-the-art trackers, and it has higher accuracy and robustness than the DSST tracker.

A Survey of Automated Threaded Fastening

Threaded fasteners are prevalent throughout modern manufacturing. Thus, as the demand for automation in manufacturing increases, so does the demand for automated threaded fastening systems. However, many fundamental issues and engineering challenges still hinder robustness in automation, particularly for smaller screws and critical product finishing requirements. This paper surveys the state of the art in threaded fastening automation and discusses open questions for further research. This survey covers the following areas: 1) fundamentals of threaded fastening, including basic concepts and definitions; 2) analysis of the entire assembly process (consisting of part feeding and orientation, pickup, alignment, and driving), including discussions of tools, control strategies, and other considerations; 3) failure modes and techniques to mitigate them; 4) threaded fastening systems and electromechanical approaches; and 5) open challenges and suggestions for future development. Understanding the current state of automation in threaded fastening will provide a foundation for researchers to advance this field. Note to Practitioners —This paper is motivated by the problem of an automated assembly of small screws, one of the most challenging problems in a smartphone assembly. It represents a rigorous review of robotic screwdriving literature to identify the state-of-the-art and open problems. The review material was targeted toward engineers working on related problems with the sponsor and has proved useful to them. To benefit researchers in the field of robotic and automated assembly, we have compiled the review material in the form of a survey paper. This paper covers theoretical fundamentals, tools, control and failure detection strategies, industrial applications, and open problems for robotic screwdriving. It provides a foundation for readers to familiarize themselves with the state of the art and conduct further research on this thread.

A novel faster failure detection strategy for link connectivity using Hello messaging in mobile ad hoc networks

Faster failure detection is one of the main steps responsible for efficient link connectivity in mobile ad hoc networks (MANETs). Under a random behaviour of network nodes and link/node failure, there must be a unified approach to describe an adequate Hello messaging strategy for link connectivity in MANETs. In order to tackle this issue, we present a strategy for achieving faster failure detection, and derive algorithmic attributes of the proposed strategy on the basis of multiple parameters of interest after modelling it as a Markov process. We also present novel algorithms to minimise the biggest chunk of delay incurred as a result of link re-connectivity and, thus, improve network connectivity in MANETs. Simulation and analytical results indicate efficacy of the proposed strategy in achieving faster failure detection and efficient link re-connectivity.

A novel faster failure detection strategy for link connectivity using Hello messaging in mobile ad hoc networks

Faster failure detection is one of the main steps responsible for efficient link connectivity in mobile ad hoc networks (MANETs). Under a random behaviour of network nodes and link/node failure, th...

A Long-term Tracking Model Based on Tracking Failure Detection Strategy and Weighted Random Forest

Compared to traditional visual tracking, long-term tracking appears to be more challenging since the target is likely to suffer more severe deformation, occlusion, scale change or move out of view scenarios. It is challenging to develop a robust and efficient target model. In this paper, we propose a robust model for long-term tracking in complex scenes. In order to achieve this goal, firstly, we extract multi-scale feature based on the illumination invariant color space to solve scale and illumination change of the target. For the purpose of reducing time consumption caused by the multi-scale feature, we adopt a random measurement matrix to project the high-dimensional multi-scale features onto a low-dimensional subspace. Secondly, we introduce a tracking Failure Detection Strategy(FDS) to decide whether the tracking is a failure which cause by occlusion, illumination change and situations when the target moves out of camera view. Finally, we proposed a Weighted Random Forest(WRF) classifier to retrieve the target position after the tracking failure situation, and the classifier is updated online, so that the performance of the model improves over time. Our proposed model performs favorably in complex scenes against conventional models in terms of robustness and time consumption.

Flight Control System improvement based on a software sensor derived from Partial Least Squares Algorithm

Global aircraft optimization is a main concern for future and upcoming programs. In particular, great research efforts are dedicated to Electrical Flight Control Systems (EFCS). Obviously, their reliability increases with the redundancy of the flight parameter sensors. However, physical redundancy, obtained by increasing the number of sensors, penalizes the aircraft weight and cost. This paper proposes a sensor failure detection method based on analytic redundancy. The flight parameter of interest is modelled as a linear function of independent sensor measurements on a sliding observation window. The Partial Least Squares (PLS) algorithm is used to estimate regression coefficients on this window. The PLS computes the solution via an iterative processing, and thus can be implemented in the flight control computer for a real time use. Two different failure detection strategies based on the behaviour of the regression coefficients are proposed. Simulation results show that the proposed method leads to robust detections.

A Failure Detection Strategy for Intrafraction Prostate Motion Monitoring With On-Board Imagers for Fixed-Gantry IMRT

To develop methods to monitor prostate intrafraction motion during fixed-gantry intensity-modulated radiotherapy using MV treatment beam imaging together with minimal kV imaging for a failure detection strategy that ensures prompt detection when target displacement exceeds a preset threshold. Real-time two-dimensional (2D) marker position in the MV image plane was obtained by analyzing cine-MV images. The marker's in-line movement, and thus its time-varying three-dimensional (3D) position, was estimated by combining the 2D projection data with a previously established correlative relationship between the directional components of prostate motion. A confirmation request for more accurate localization using MV-kV triangulation was triggered when the estimated prostate displacement based on the cine-MV data was greater than 3 mm. An interventional action alert followed on positive MV-kV confirmation. To demonstrate the feasibility and accuracy of the proposed method, simulation studies of conventional-fraction intensity-modulated radiotherapy sessions were done using 536 Calypso-measured prostate trajectories from 17 radiotherapy patients. A technique for intrafraction prostate motion management has been developed. The technique, using "freely available" cine-MV images and minimum on-board kV imaging (on average 2.5 images/fraction), successfully limited 3D prostate movement to within a range of 3 mm relative to the MV beam for 99.4% of the total treatment time. On average, only approximately one intervention/fraction was needed to achieve this level of accuracy. Instead of seeking to accurately and continuously localize the prostate target as existing motion tracking systems do, the present technique effectively uses cine-MV data to provide a clinically valuable way to minimize kV usage, while maintaining high targeting accuracy.

An autonomic failure-detection algorithm

Designs for distributed systems must consider the possibility that failures will arise and must adopt specific failure detection strategies. We describe and analyze a self-regulating failure-detection algorithm that bounds resource usage and failure-detection latency, while automatically reassigning resources to improve failure-detection latency as system size decreases. We apply the algorithm to (1) Jini leasing, (2) service registration in the Service Location Protocol (SLP), and (3) SLP service polling

A robust failure diagnostic system for thermofluid processes

Recent advances in microprocessor technology have enabled the application of process diagnostics to a variety of systems for improved performance and reliability. Failure detection and isolation strategies monitor a system's operation for degradations, and if detected, classify the failure source. In this paper, an on-board diagnostic system will be presented for small-scale thermofluid processes. A model-free limit and trend checking scheme, and a model-based innovations failure detection strategy monitor the system in parallel to detect anomalous behaviour. An experimental-based multiple hypothesis failure isolation strategy statistically classifies the degradations using an a priori failure database. To demonstrate the diagnostic system's performance, a series of failures have been experimentally induced, detected and classified in a residential refrigerator.

A failure detection method for integrated voice/data packet networks

A failure detection strategy at the data-link layer, implementable between frame-relay network nodes, is described for integrated voice/data packet networks. This strategy makes it possible to respond to link failures early enough to maintain data-session continuity. A simple, two-phase approach is proposed. In the first phase, the presence of a bit error rate violation along the packet link during short, fixed-length time segments is determined. In the second phase, the failure decision is made on the basis of a sequential algorithm. A simple table lookup implementation of the algorithm that requires no real-time computation is described. >

Self-healing in wideband packet networks

A brief overview is given of wideband packet technology (WPT), with special attention to the features affecting the feasibility of self-healing, a method for automatic failure recovery proposed herein. The objectives of self-healing are set forth, and the failure detection strategy is described. With this strategy, nondisruptive trunk monitoring (self-monitoring) at the data link layer of an open system interconnection (OSI) reference model is performed to detect facility failure of under 1 s. The bit error rate (BER) on a transmission link is estimated on the basis of counts of the number of packets with cyclic redundancy check (CRC) errors at the data link layer. This failure detection strategy can respond to link failures for any given traffic mix by the provisioning of duration and level of unacceptable sustained BER. The mechanisms used to achieve recovery in frame-relay networks using packet streams to carry users' traffic are discussed. Provisioning of the WPT nodes and the network is addressed. >