A high order collaboration and real time formal model for automatic testing of safety critical systems

The need for safety critical systems （SCS） is both important and urgent, and their evaluation and verification are test-dependent. SCS are usually complex and very large, so manual testing of SCS are infeasible in practice, and develop- ing automatic test approaches for SCS has become an impor- tant trend. This paper defines a formal semantics model for automatic test of SCS, called AutTMSCS, which describes behaviors in SCS testing. The model accommodates the high order collaboration in real time and temporariness of SCS testing. Testing tasks, test equipment and products under test are abstracted and architected in three layers, and a method for automatic testing is given. Based on extended label tran- sition system （LTS）, the convergency and correctness of the model are proved to demonstrate the computability of the model, indicating that the testing process of SCS can be au- tomatic.

Investigating safety and liability of autonomous vehicles:Bayesian random parameter ordered probit model analysis

Purpose–This study aims to investigate the safety and liability of autonomous vehicles(AVs),and identify the contributing factors quantitatively so as to provide potential insights on safety and liability of AVs.Design/methodology/approach–The actual crash data were obtained from California DMV and Sohu websites involved in collisions of AVs from 2015 to 2021 with 210 observations.The Bayesian random parameter ordered probit model was proposed to reflect the safety and liability of AVs,respectively,as well as accommodating the heterogeneity issue simultaneously.Findings–The findings show that day,location and crash type were significant factors of injury severity while location and crash reason were significant influencing the liability.Originality/value–The results provide meaningful countermeasures to support the policymakers or practitioners making strategies or regulations about AV safety and liability.

Understanding the relationship between High Reliability Theory (HRT) ofmindful organizing and Safety Management Systems (SMS) within theaerospace industry: A cross-sectional quantitative assessment

There seems to be a paucity in extant literature that assesses the relationship between Safety Management Systems (SMS) and High Reliability Theory (HRT) behavior process of mindful organizing (MO) among aerospaceorganizations. There could be benefits for organizational safety by exploring this relationship in high-reliabilityorganizations (HROs) like the aerospace industry. Using a modified Safety Organizing Scale (SOS) by Vogus andSutcliffe (2007) and a validated SMS scale, the relationship between SMS and MO was measured. The perceptionsof a cross-section of respondents from commercial airlines with SMS and commercial space licensees without SMSin the United States (U.S.) was assessed. A four-factor model of MO had acceptable fit. A model showing the relationship between SMS and MO had good fit and showed a high significant strength of relationship (r = 0.82,p = 0.000) with a big effect size. There were also significant differences in mean responses among managementpersonnel and non-management personnel on the MO factor “sensitivity to operations” and the result suggestsmanagers were better at identifying personnel with skills and knowledge to ensure safer task accomplishmentthan non-management personnel. The study results suggest that the SMS requirements for commercial airlines inthe U.S. can enrich the identification and understanding of MO factors and it may be beneficial for the commercial space industry to formally adopt SMS. Future research studies may include direct comparisons in multipleaerospace organizations using a larger sample size to determine the overall understanding of MO factors and howit affects SMS.

In-service performance of emergency shutdown valves and dependent operational relationships in the offshore oil and gas industry

Industrial process plants use emergency shutdown valves(ESDVs)as safety barriers to protect against hazardous events,bringing the plant to a safe state when potential danger is detected.These ESDVs are used extensively in offshore oil and gas processing plants and have been mandated in the design of such systems from national and international standards and legislation.This paper has used actual ESDV operating data from four mid/late life oil and gas production platforms in the North Sea to research operational relationships that are of interest to those responsible for the technical management and operation of ESDVs.The first of the two relationships is between the closure time(CT)of the ESDV and the time it remains in the open position,prior to the close command.It has been hypothesised that the CT of the ESDV is affected by the length of time that it has been open prior to being closed(Time since the last stroke).In addition to the general analysis of the data series,two sub-categories were created to further investigate this possible relationship for CT and these are“above mean”and“below mean”.The correlations(Pearson's based)resulting from this analysis are in the“weak”and“very weak”categories.The second relationship investigated was the effect of very frequent closures to assess if this improves the CT.ESDV operational records for six subjects were analysed to find closures that occurred within a 24 h period of each other.However,no discriminating trend was apparent where CT was impacted positively or negatively by the frequent closure group.It was concluded that the variance of ESDV closure time cannot be influenced by the technical management of the ESDV in terms of scheduling the operation of the ESDV.

基于碰撞检测的自适应阻抗控制机械臂系统(英文)

This article provides a flexible-joint-manipulator,which incorporates with three means to make its mechanical arm come into compliant contact with the objects with a force kept within an acceptable range. At first,the Cartesian impedance control law is introduced on the basis of virtual decomposition to realize the compliance control. Then,adaptive dynamic joint compensators on all joints are used to achieve more precise control. Finally,a Cartesian force-feedback path generation is developed for collision ...

Investigation of drinking water bacterial community through high-throughput sequencing

Delivery of safe and pathogen-free drinking water is crucial to public health.However,there exist challenges to the maintenance of the sterility of drinking water throughout the drinking water distribution systems（DWDS）.Microbial growth in DWDS,such as growth of opportunistic pathogenic microorganisms,can lead to severe health problems in consumers（Berry et al.,2006;Brettar and Hofle,2006;Lu et al.,2014;Zhang et al.,2015）.

A novel intelligent vehicle risk assessment method combined with multi-sensor fusion in dense traffic environment

Purpose–The purpose of this paper is to accurately capture the risks which are caused by each road user in time.Design/methodology/approach–The authors proposed a novel risk assessment approach based on the multi-sensor fusion algorithm in the real traffic environment.Firstly,they proposed a novel detection-level fusion approach for multi-object perception in dense traffic environment based on evidence theory.This approach integrated four states of track life into a generic fusion framework to improve the performance of multi-object perception.The information of object type,position and velocity was accurately obtained.Then,they conducted several experiments in real dense traffic environment on highways and urban roads,which enabled them to propose a novel road traffic risk modeling approach based on the dynamic analysis of vehicles in a variety of driving scenarios.By analyzing the generation process of traffic risks between vehicles and the road environment,the equivalent forces of vehicle–vehicle and vehicle–road were presented and theoretically calculated.The prediction steering angle and trajectory were considered in the determination of traffic risk influence area.Findings–The results of multi-object perception in the experiments showed that the proposed fusion approach achieved low false and missing tracking,and the road traffic risk was described as afield of equivalent force.The results extend the understanding of the traffic risk,which supported that the traffic risk from the front and back of the vehicle can be perceived in advance.Originality/value–This approach integrated four states of track life into a generic fusion framework to improve the performance of multi-object perception.The information of object type,position and velocity was used to reduce erroneous data association between tracks and detections.Then,the authors conducted several experiments in real dense traffic environment on highways and urban roads,which enabled them to propose a novel road traffic risk modeling approach based on the dynamic analysis of vehicles in a variety of driving scenarios.By analyzing the generation process of traffic risks between vehicles and the road environment,the equivalent forces of vehicle–vehicle and vehicle–road were presented and theoretically calculated.